<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v2.0 20040830//EN" "journalpublishing.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="2.0" xml:lang="en" article-type="research-article"><front><journal-meta><journal-id journal-id-type="nlm-ta">J Med Internet Res</journal-id><journal-id journal-id-type="publisher-id">jmir</journal-id><journal-id journal-id-type="index">1</journal-id><journal-title>Journal of Medical Internet Research</journal-title><abbrev-journal-title>J Med Internet Res</abbrev-journal-title><issn pub-type="epub">1438-8871</issn><publisher><publisher-name>JMIR Publications</publisher-name><publisher-loc>Toronto, Canada</publisher-loc></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">v28i1e89136</article-id><article-id pub-id-type="doi">10.2196/89136</article-id><article-categories><subj-group subj-group-type="heading"><subject>Original Paper</subject></subj-group></article-categories><title-group><article-title>Factors Associated With Digital Health Literacy in the United Kingdom: Cross-Sectional Online Survey</article-title></title-group><contrib-group><contrib contrib-type="author"><name name-style="western"><surname>Exton-Smith</surname><given-names>Holly</given-names></name><degrees>MSci, MPH</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Sousi</surname><given-names>Sara</given-names></name><degrees>BSc (Hons), MRes</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Alharbi</surname><given-names>Albandari</given-names></name><degrees>BA, MSc</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>El-Osta</surname><given-names>Austen</given-names></name><degrees>MPA, PhD</degrees><xref ref-type="aff" rid="aff2">2</xref></contrib><contrib contrib-type="author" corresp="yes"><name name-style="western"><surname>Greenfield</surname><given-names>Geva</given-names></name><degrees>PhD</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Hayhoe</surname><given-names>Benedict</given-names></name><degrees>MBBS</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Majeed</surname><given-names>Azeem</given-names></name><degrees>MD, FMedSci, FRCP, FRCGP, FFPH</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib><contrib contrib-type="author"><name name-style="western"><surname>Lu&#x00ED;sa Neves</surname><given-names>Ana</given-names></name><degrees>MBBS, PhD</degrees><xref ref-type="aff" rid="aff1">1</xref></contrib></contrib-group><aff id="aff1"><institution>Department of Primary Care and Public Health, School of Public Health, Imperial College London</institution><addr-line>90 Wood Lane</addr-line><addr-line>London</addr-line><addr-line>England</addr-line><country>United Kingdom</country></aff><aff id="aff2"><institution>Self-Care Academic Research Unit (SCARU), Department of Primary Care and Public Health, Imperial College London</institution><addr-line>London</addr-line><addr-line>England</addr-line><country>United Kingdom</country></aff><contrib-group><contrib contrib-type="editor"><name name-style="western"><surname>Stone</surname><given-names>Alicia</given-names></name></contrib></contrib-group><contrib-group><contrib contrib-type="reviewer"><name name-style="western"><surname>Pabon-Rodriguez</surname><given-names>Felix</given-names></name></contrib><contrib contrib-type="reviewer"><name name-style="western"><surname>Vundavalli</surname><given-names>Harish</given-names></name></contrib><contrib contrib-type="reviewer"><name name-style="western"><surname>Liu</surname><given-names>Zhao</given-names></name></contrib></contrib-group><author-notes><corresp>Correspondence to Geva Greenfield, PhD, Department of Primary Care and Public Health, School of Public Health, Imperial College London, 90 Wood Lane, London, W12 0BZ, England, United Kingdom, 44 020 7589 5111; <email>g.greenfield@imperial.ac.uk</email></corresp></author-notes><pub-date pub-type="collection"><year>2026</year></pub-date><pub-date pub-type="epub"><day>8</day><month>7</month><year>2026</year></pub-date><volume>28</volume><elocation-id>e89136</elocation-id><history><date date-type="received"><day>07</day><month>12</month><year>2025</year></date><date date-type="rev-recd"><day>22</day><month>05</month><year>2026</year></date><date date-type="accepted"><day>26</day><month>05</month><year>2026</year></date></history><copyright-statement>&#x00A9; Holly Exton-Smith, Sara Sousi, Albandari Alharbi, Austen El-Osta, Geva Greenfield, Benedict Hayhoe, Azeem Majeed, Ana Lu&#x00ED;sa Neves. Originally published in the Journal of Medical Internet Research (<ext-link ext-link-type="uri" xlink:href="https://www.jmir.org">https://www.jmir.org</ext-link>), 8.7.2026. </copyright-statement><copyright-year>2026</copyright-year><license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (<ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link>), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research (ISSN 1438-8871), is properly cited. The complete bibliographic information, a link to the original publication on <ext-link ext-link-type="uri" xlink:href="https://www.jmir.org/">https://www.jmir.org/</ext-link>, as well as this copyright and license information must be included.</p></license><self-uri xlink:type="simple" xlink:href="https://www.jmir.org/2026/1/e89136"/><abstract><sec><title>Background</title><p>Digital health literacy (DHL), the ability to seek, understand, and apply digital health information, is increasingly important in the United Kingdom, with a focus on digital transformation within the health service. While digital tools offer potential to improve access and equity, they may exacerbate existing health inequities if segments of the population are unable to engage with them effectively. Understanding the sociodemographic, economic, and social factors associated with DHL is essential to designing inclusive digital health services.</p></sec><sec><title>Objective</title><p>This study aimed to measure DHL among UK adults and identify its sociodemographic, economic, and social associates.</p></sec><sec sec-type="methods"><title>Methods</title><p>A cross-sectional online survey was disseminated to a nationally representative sample of UK adult internet users from November to December 2024. DHL was self-reported using the validated eHealth Literacy Scale (eHEALS), which ranges from 8 to 40. eHEALS score was dichotomized into high and low DHL based on a cutoff of 26. Multivariable logistic regression was used to identify associates of DHL, with missing data handled using multiple imputation by chained equations.</p></sec><sec sec-type="results"><title>Results</title><p>The median eHEALS score was 31 (IQR 27&#x2010;32); 21% (320/1525) of the participants had low DHL, while 79% (1205/1525) had high DHL. Those aged 65 years and older, compared with those in the age group of 18&#x2010;44 years, had higher odds of low DHL (odds ratio [OR] 1.43, 95% CI 1.02&#x2010;2.01; <italic>P</italic>=.04). Those belonging to a lower social grade also had higher odds of low DHL, compared with those belonging to the higher social grade (OR 1.37, 95% CI 1.05&#x2010;1.80; <italic>P</italic>=.02). Females had lower odds of low DHL (OR 0.60, 95% CI 0.46&#x2010;0.77; <italic>P</italic>&#x003C;.001), as did those with an undergraduate or postgraduate degree or higher, compared with those educated to below degree level (undergraduate degree OR 0.52, 95% CI 0.37&#x2010;0.74, <italic>P</italic>&#x003C;.001; postgraduate degree or higher OR 0.58, 95% CI 0.40&#x2010;0.82, <italic>P</italic>=.002). Those who socialized daily, compared to those who did this never or rarely, had marginally lower odds of low DHL (OR 0.64, 95% CI 0.42&#x2010;1.00; <italic>P</italic>=.05). In subgroup analysis among participants with chronic health conditions, age and social grade were not significant associates of DHL.</p></sec><sec sec-type="conclusions"><title>Conclusions</title><p>Among UK internet users, male sex, lower educational attainment, lower social grade, less frequent socializing, and older age were statistically significant associates of low DHL. The model&#x2019;s modest explanatory power suggests that additional factors beyond those examined play an important role. As findings are based on internet users, the prevalence of low DHL in the general population is likely higher than reported. This study provides a partial basis for identifying groups who may benefit from additional support, but intervention design should not rely solely on factors identified here. Inclusive interventions accounting for a broader range of factors are needed to ensure that digital transformation in health care narrows rather than widens health inequities.</p></sec></abstract><kwd-group><kwd>digital health</kwd><kwd>eHealth literacy</kwd><kwd>health inequalities</kwd><kwd>cross-sectional studies</kwd><kwd>online survey</kwd><kwd>digital health literacy</kwd><kwd>eHealth Literacy Scale</kwd><kwd>equity</kwd><kwd>digital tools</kwd></kwd-group></article-meta></front><body><sec id="s1" sec-type="intro"><title>Introduction</title><p>Digital health encompasses the use of digital technologies to improve health and health care delivery [<xref ref-type="bibr" rid="ref1">1</xref>]. Early examples include telemedicine, online health information, and electronic health records, while wearable technologies for health (wearables), mobile device apps, online communities, and social media are more recent developments [<xref ref-type="bibr" rid="ref2">2</xref>]. These tools are changing the way populations access health care and communicate with health care professionals, as well as how we monitor symptoms, manage diseases, and track our health more generally. The National Health Service (NHS) in the United Kingdom has a digital strategy, which includes digital general practice services and electronic prescriptions [<xref ref-type="bibr" rid="ref3">3</xref>,<xref ref-type="bibr" rid="ref4">4</xref>]. Based on findings from an investigation of the current state of the NHS in England [<xref ref-type="bibr" rid="ref5">5</xref>], digital transformation is 1 of 3 shifts outlined in the recent 10 Year Health Plan for England [<xref ref-type="bibr" rid="ref4">4</xref>].</p><p>Health literacy is widely recognized as a determinant of health outcomes and a major public health challenge [<xref ref-type="bibr" rid="ref6">6</xref>-<xref ref-type="bibr" rid="ref9">9</xref>]. Improved digital health literacy (DHL) is crucial for navigating digital health technologies and maximizing the benefits of modern health care [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref11">11</xref>]. DHL is defined as the ability to search, find, understand, and evaluate health information from electronic resources and to use the knowledge gained to solve health-related problems [<xref ref-type="bibr" rid="ref12">12</xref>]. DHL can facilitate self-management of health [<xref ref-type="bibr" rid="ref13">13</xref>,<xref ref-type="bibr" rid="ref14">14</xref>], mitigate the effects of digital misinformation [<xref ref-type="bibr" rid="ref15">15</xref>-<xref ref-type="bibr" rid="ref17">17</xref>], and improve access to health care [<xref ref-type="bibr" rid="ref18">18</xref>,<xref ref-type="bibr" rid="ref19">19</xref>]. Several tools have been developed to measure DHL, with the most used being the eHealth Literacy Scale (eHEALS) [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref20">20</xref>].</p><p>eHEALS has been validated in a range of languages (including German and Dutch [<xref ref-type="bibr" rid="ref21">21</xref>,<xref ref-type="bibr" rid="ref22">22</xref>]), settings (including high- and low-income countries [<xref ref-type="bibr" rid="ref22">22</xref>,<xref ref-type="bibr" rid="ref23">23</xref>]), and social groups (including university students and older adults [<xref ref-type="bibr" rid="ref14">14</xref>,<xref ref-type="bibr" rid="ref24">24</xref>-<xref ref-type="bibr" rid="ref26">26</xref>]). eHEALS has demonstrated good internal consistency, with Cronbach &#x03B1; values typically ranging from 0.88 to 0.93 across studies [<xref ref-type="bibr" rid="ref21">21</xref>,<xref ref-type="bibr" rid="ref27">27</xref>,<xref ref-type="bibr" rid="ref28">28</xref>]. Norman and Skinner [<xref ref-type="bibr" rid="ref28">28</xref>] found the tool to have a single-factor structure in their sample of adolescents; however, subsequent studies have found it to have a 1-, 2-, or 3-factor structure among different populations [<xref ref-type="bibr" rid="ref22">22</xref>,<xref ref-type="bibr" rid="ref29">29</xref>]. The tool&#x2019;s brevity makes it popular in both research and clinical settings [<xref ref-type="bibr" rid="ref30">30</xref>].</p><p>Given the importance of DHL, several studies have investigated its associates. However, most studies have focused on a specific population, and their ability to generalize findings to the UK population is limited [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref31">31</xref>]. In addition, studies have focused on a narrow scope of possible associates, potentially neglecting other factors that influence DHL. Despite these limitations, certain relationships have been identified in the literature. Older age is consistently found to be an associate of low DHL [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref32">32</xref>,<xref ref-type="bibr" rid="ref33">33</xref>], while higher educational attainment and higher socioeconomic status have been found to positively affect DHL [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref31">31</xref>,<xref ref-type="bibr" rid="ref33">33</xref>]. Other factors&#x2014;such as urbanicity, ethnicity, primary language, employment status, and social support&#x2014;are also possible determinants of DHL [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref33">33</xref>-<xref ref-type="bibr" rid="ref36">36</xref>]. However, further investigation is warranted. Additionally, health conditions and self-perceived health status may influence DHL. A cross-European study found that self-reported health was a positive determinant of eHEALS score [<xref ref-type="bibr" rid="ref32">32</xref>], and better self-reported health status has been shown to be associated with DHL skills, after adjusting for various socioeconomic factors and use of the internet for seeking health-related information [<xref ref-type="bibr" rid="ref17">17</xref>]. Notably, respondents with a long-term disease also exhibited increased agreement with DHL-related skills [<xref ref-type="bibr" rid="ref17">17</xref>]. In contrast, a meta-analysis across 7 studies found that participants with existing disease or at a higher risk for disease had lower eHEALS scores [<xref ref-type="bibr" rid="ref31">31</xref>]. These findings highlight the challenge in parsing the influence of chronic health conditions compared with perceived health status [<xref ref-type="bibr" rid="ref17">17</xref>,<xref ref-type="bibr" rid="ref21">21</xref>,<xref ref-type="bibr" rid="ref22">22</xref>].</p><p>The aim of this study was to measure DHL among adults in the United Kingdom and identify associated sociodemographic, economic, and social factors. A better understanding of both the DHL level and the factors associated with it in the United Kingdom will be critical to inform the design of more tailored digital health tools and targeted interventions. This ensures that those who need health information can access, understand, and apply it [<xref ref-type="bibr" rid="ref21">21</xref>], thereby contributing to improved health outcomes.</p></sec><sec id="s2" sec-type="methods"><title>Methods</title><sec id="s2-1"><title>Study Design and Setting</title><p>A cross-sectional 10-minute survey was conducted among the UK adult population. The web-based survey was administered through YouGov from November 22 to December 4, 2024. This study was a secondary analysis of the dataset collected. The study used the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for cross-sectional studies [<xref ref-type="bibr" rid="ref37">37</xref>] (<xref ref-type="supplementary-material" rid="app9">Checklist 1</xref>).</p></sec><sec id="s2-2"><title>Participants</title><p>Upon signing up to YouGov, prospective respondents agreed to their terms and conditions and acknowledged the privacy notice [<xref ref-type="bibr" rid="ref38">38</xref>,<xref ref-type="bibr" rid="ref39">39</xref>]. YouGov panel members received an email invitation that introduced the study and included a link to the web-based survey. Participants were required to be internet users, aged 18 years or older, live in the United Kingdom, and able to complete the survey in English. Quotas were used to aim for representativeness with regard to age, sex, region, ethnicity, and National Readership Survey (NRS) social grade [<xref ref-type="bibr" rid="ref40">40</xref>]. Participants received 50 points on the YouGov platform to compensate them for their time, the equivalent of &#x00A3;0.50 (approximately US $0.67).</p></sec><sec id="s2-3"><title>Sample Size</title><p>A minimum sample size was calculated using the formula:</p><disp-formula id="equWL1"><mml:math id="eqn1"><mml:mstyle displaystyle="true" scriptlevel="0"><mml:mrow><mml:mstyle displaystyle="true" scriptlevel="0"><mml:mi>n</mml:mi><mml:mo>=</mml:mo><mml:mfrac><mml:mrow><mml:msup><mml:mi>Z</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mtext>&#x00A0;</mml:mtext><mml:mi>p</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>1</mml:mn><mml:mo>&#x2212;</mml:mo><mml:mi>p</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:msup><mml:mi>&#x03B5;</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:mfrac></mml:mstyle></mml:mrow></mml:mstyle></mml:math></disp-formula><p>where <italic>n</italic> is the required sample size, <italic>Z</italic> is the <italic>Z</italic> score, <italic>p</italic> is the estimated population proportion, and <italic>&#x03B5;</italic> is the margin of error. Assuming a 95% CI (<italic>Z</italic>=1.96), a conservative estimated proportion (<italic>p</italic>=0.5), and a margin of error of 5% (<italic>&#x03B5;</italic>=0.05), the minimum required sample size was calculated to be 385. Given the large population size of 52.8 million people aged 20 years and older in the United Kingdom [<xref ref-type="bibr" rid="ref41">41</xref>], a finite population correction was not applied as it would have a negligible effect on the estimate. A final sample of 1525 participants was included in the analysis.</p></sec><sec id="s2-4"><title>Survey Development</title><p>The survey was developed by a multidisciplinary team comprising medical doctors, nurses, and health services researchers. The questionnaire operationalized the PROGRESS-Plus framework, which illustrates the multiple factors that can contribute to health inequalities in a population [<xref ref-type="bibr" rid="ref42">42</xref>,<xref ref-type="bibr" rid="ref43">43</xref>]. It collected information on participants&#x2019; sociodemographic, economic, and social characteristics, as well as data about health and DHL (<xref ref-type="supplementary-material" rid="app1">Multimedia Appendix 1</xref>).</p></sec><sec id="s2-5"><title>Ethical Considerations</title><p>Consent to enter the study was sought from each participant after a full explanation was given and before accessing the survey. All participants were free to withdraw at any time by closing the browser window where they were completing the survey; there were no consequences for withdrawal. Study participants and YouGov gave permission for these data to be used for research purposes. Approval for this study was obtained from the Head of Department and the Research Governance and Integrity Team (reference 7750506); the study was also registered and approved via Imperial&#x2019;s Data Asset Registration Tool. The study followed the ethical principles of the World Medical Association outlined in the Declaration of Helsinki and subsequent amendments [<xref ref-type="bibr" rid="ref44">44</xref>].</p></sec><sec id="s2-6"><title>Variables</title><p>The predictor variables analyzed were UK region, urbanicity, ethnicity, primary language spoken within the household, employment status, sex, religion, educational attainment, annual household income, NRS social grade [<xref ref-type="bibr" rid="ref40">40</xref>], frequency of meeting friends and family, age group, presence of health conditions, and limitations to daily activities. These characteristics were mapped against the PROGRESS-Plus framework [<xref ref-type="bibr" rid="ref42">42</xref>], as shown in <xref ref-type="supplementary-material" rid="app1">Multimedia Appendix 1</xref>. Urbanicity was measured using self-report; participants were asked &#x201C;Do you live in an urban, suburban, or rural area?&#x201D; with answer options urban, suburban, rural. At the analysis stage, this variable was dichotomized to give urban and nonurban as groups. NRS social grade is a classification system based on the occupation of the household&#x2019;s chief income earner, their qualifications, and the number of people they are responsible for [<xref ref-type="bibr" rid="ref40">40</xref>]. This yields 6 categories, A, B, C1, C2, D, and E, with A representing higher managerial roles and E representing casual or lowest grade workers, or those who are unemployed and on state benefits or pensions [<xref ref-type="bibr" rid="ref40">40</xref>]. These groups were recategorized to give ABC1 and C2DE, where the latter is the lower social grade.</p><p>The outcome variable was DHL, as measured by eHEALS [<xref ref-type="bibr" rid="ref28">28</xref>]. This is a simple, 8-item tool, including items such as &#x201C;I know how to use the Internet to answer my health questions&#x201D; and &#x201C;I can tell high quality from low quality health resources on the Internet&#x201D; [<xref ref-type="bibr" rid="ref28">28</xref>] (<xref ref-type="supplementary-material" rid="app2">Multimedia Appendix 2</xref>). Each item uses a 5-point Likert scale with response options ranging from &#x201C;strongly disagree&#x201D; to &#x201C;strongly agree&#x201D; [<xref ref-type="bibr" rid="ref28">28</xref>]. Overall eHEALS score was calculated by summing answers across the 8 items for each participant, giving a final score from 8 to 40 [<xref ref-type="bibr" rid="ref28">28</xref>]. In this study, eHEALS was dichotomized to present high and low DHL, with a score &#x003C;26 representing low DHL [<xref ref-type="bibr" rid="ref34">34</xref>,<xref ref-type="bibr" rid="ref45">45</xref>-<xref ref-type="bibr" rid="ref47">47</xref>]. This cutoff was first applied by Richtering et al [<xref ref-type="bibr" rid="ref45">45</xref>] and has since been adopted across multiple studies, facilitating comparison with the existing literature [<xref ref-type="bibr" rid="ref34">34</xref>,<xref ref-type="bibr" rid="ref46">46</xref>,<xref ref-type="bibr" rid="ref47">47</xref>]. The internal consistency of eHEALS data in this sample was calculated using Cronbach &#x03B1;.</p></sec><sec id="s2-7"><title>Statistical Analysis</title><p>Descriptive statistics were performed using total and relative frequencies for categorical variables. Participants categorized as having low and high DHL were compared using bivariate analysis. Prior to analysis, linear regression using the continuous eHEALS score was explored; however, model diagnostics indicated that key assumptions were violated, including constant variance and normality of residuals, likely reflecting the nonnormal distribution of eHEALS score in this sample. Logistic regression using a dichotomized eHEALS score was therefore adopted as the primary analytical approach. Predictor reference categories were selected based on theoretical relevance and interpretability. A multivariable logistic regression model was built using the enter method where all possible predictors were included as independent variables, irrespective of their significance at the univariable analysis stage. Before building the multivariable model, associations between predictor variables were assessed to check for multicollinearity. Chi-square tests (or Fisher exact tests where expected cell count was &#x003C;5) were used for this purpose; predictors were omitted from the multivariable model where the association between them was considered problematic, defined as <italic>P</italic>&#x003C;.05 and Cramer V&#x2265;0.3. After investigation of associations between predictor variables, region, employment status, primary language, income, and health condition were omitted from the multivariable model due to problematic associations with other predictors.</p><p>Descriptive statistics and prevalence estimates were calculated using the full sample. Most variables had low levels of missingness (0%&#x2010;5%), with the exception of income; income was excluded from the multivariable model on this basis, alongside multicollinearity with other variables. Little&#x2019;s missing completely at random (MCAR) test [<xref ref-type="bibr" rid="ref48">48</xref>] indicated that data were not MCAR. Further analysis revealed that missingness in certain sociodemographic variables, namely, education and limited daily activities, was associated with significantly lower DHL scores, suggesting a systematic relationship between missingness and the outcome. Multiple imputation by chained equations (MICE) was therefore used as the primary approach to handle missing data, using the mice package in R (R Core Team) [<xref ref-type="bibr" rid="ref49">49</xref>-<xref ref-type="bibr" rid="ref51">51</xref>]. Twenty imputed datasets were generated, reflecting the proportion of incomplete cases in the analytical sample (198/1525, 13%) [<xref ref-type="bibr" rid="ref52">52</xref>]. Appropriate imputation methods were specified for each variable type: logistic regression for binary variables (namely, urbanicity, religion, and limited daily activities) and polytomous logistic regression for unordered categorical variables with more than 2 levels (namely, education). All covariates from the multivariable model and outcome variable of DHL were included in the imputation model, alongside auxiliary variables (region, employment status, primary language, income, and health condition) to improve imputation quality. Convergence was assessed visually using trace plots, and the distribution of imputed values was compared with observed distributions to verify plausibility. The logistic regression model was fitted within each imputed dataset, and results were pooled using Rubin&#x2019;s rules [<xref ref-type="bibr" rid="ref49">49</xref>,<xref ref-type="bibr" rid="ref50">50</xref>].</p><p>The estimated effects on DHL were expressed as odds ratios (ORs), alongside 95% CIs for each variable; these values were adjusted for all other variables in the multivariable model. <italic>P</italic> values were also reported, with <italic>P</italic> values &#x003C;.05 considered statistically significant. All analysis was performed using R software (version 4.4.2; R Core Team) [<xref ref-type="bibr" rid="ref53">53</xref>].</p></sec><sec id="s2-8"><title>Sensitivity Analyses</title><p>Given the unclear and contradictory relationship between health conditions and DHL reported in the literature [<xref ref-type="bibr" rid="ref17">17</xref>,<xref ref-type="bibr" rid="ref31">31</xref>,<xref ref-type="bibr" rid="ref32">32</xref>], a subgroup analysis was conducted among participants who reported any health condition to explore whether health condition status modified the relationship between sociodemographic, economic, and social factors and DHL. Univariable and multivariable logistic regression was repeated within this subgroup, using the same predictor variables as the primary analysis, with health condition excluded as a predictor given that all participants in this subgroup reported at least 1 condition.</p><p>To assess the robustness of findings to the eHEALS cutoff, a sensitivity analysis was conducted using the sample median, 31, as an alternative threshold. To explore potential effect modification, interaction terms for theoretically motivated pairs of predictors (age by sex, age by education, and sex by education) were tested alongside the primary model. To assess the potential impact of missing data on regression estimates, complete case analysis (CCA) was conducted as a sensitivity analysis alongside the primary multiple imputation analysis, resulting in the exclusion of 198 (198/1525, 13%) participants from the multivariable analysis. McFadden adjusted <italic>R</italic><sup>2</sup>, the likelihood ratio test, and Akaike Information Criterion (AIC) were used to assess explanatory power and fit for the CCA model. As these statistics are not straightforwardly pooled after MICE [<xref ref-type="bibr" rid="ref51">51</xref>], and no fully standardized approach currently exists, they are reported for the CCA only.</p></sec></sec><sec id="s3" sec-type="results"><title>Results</title><sec id="s3-1"><title>Descriptive Characterization of Participants</title><p>The final sample analyzed consisted of 1525 participants, giving a completion rate of 89.2%, as illustrated in <xref ref-type="fig" rid="figure1">Figure 1</xref>. Due to the survey approach, it was not possible to determine reasons for dropout. The majority of respondents lived in England (n=1281, 84%), in urban areas (n=1144, 75%), and were of White ethnicity (n=1349, 88.5%) (<xref ref-type="table" rid="table1">Table 1</xref>). A quarter of respondents were aged&#x2009;65 years or older (n=371, 24.3%) and just less than half were male (n=734, 48.1%) (<xref ref-type="table" rid="table1">Table 1</xref>). Over half (n=881, 57.8%) of the sample were in employment, while 24.3% (n=370) were retired. Half reported below degree level education (n=747, 49.0%) (<xref ref-type="table" rid="table1">Table 1</xref>).</p><fig position="float" id="figure1"><label>Figure 1.</label><caption><p>Study sample flow diagram.</p></caption><graphic alt-version="no" mimetype="image" position="float" xlink:type="simple" xlink:href="jmir_v28i1e89136_fig01.png"/></fig><table-wrap id="t1" position="float"><label>Table 1.</label><caption><p>Participants&#x2019; characteristics, including DHL<sup><xref ref-type="table-fn" rid="table1fn1">a</xref></sup>, and sociodemographic, economic, social, and health characteristics, total and split by DHL level.</p></caption><table id="table1" frame="hsides" rules="groups"><thead><tr><td align="left" valign="bottom">Variable</td><td align="left" valign="bottom">Total (N=1525)</td><td align="left" valign="bottom">Low DHL (n=320)</td><td align="left" valign="bottom">High DHL (n=1205)</td><td align="left" valign="bottom"><italic>P</italic> value<sup><xref ref-type="table-fn" rid="table1fn2">b</xref></sup></td></tr></thead><tbody><tr><td align="left" valign="top">eHEALS<sup><xref ref-type="table-fn" rid="table1fn3">c</xref></sup>, median (IQR)</td><td align="left" valign="top">31 (27&#x2010;32)</td><td align="left" valign="top">22 (19&#x2010;24)</td><td align="left" valign="top">32 (30&#x2010;33)</td><td align="left" valign="top">&#x003C;.001</td></tr><tr><td align="left" valign="top">UK region, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">.44</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>England</td><td align="left" valign="top">1281 (84)</td><td align="left" valign="top">261 (81.56)</td><td align="left" valign="top">1020 (84.65)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Wales</td><td align="left" valign="top">81 (5.31)</td><td align="left" valign="top">17 (5.31)</td><td align="left" valign="top">64 (5.31)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Scotland</td><td align="left" valign="top">135 (8.85)</td><td align="left" valign="top">34 (10.63)</td><td align="left" valign="top">101 (8.38)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Northern Ireland</td><td align="left" valign="top">28 (1.84)</td><td align="left" valign="top">8 (2.50)</td><td align="left" valign="top">20 (1.66)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Urbanicity, n (%) <sup><xref ref-type="table-fn" rid="table1fn4">d</xref></sup></td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">.21</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Urban</td><td align="left" valign="top">1144 (75.02)</td><td align="left" valign="top">232 (72.50)</td><td align="left" valign="top">912 (75.68)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Nonurban</td><td align="left" valign="top">316 (20.72)</td><td align="left" valign="top">69 (21.56)</td><td align="left" valign="top">247 (20.50)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">65 (4.26)</td><td align="left" valign="top">19 (5.94)</td><td align="left" valign="top">46 (3.82)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Ethnicity, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">.50</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>White</td><td align="left" valign="top">1349 (88.46)</td><td align="left" valign="top">287 (89.69)</td><td align="left" valign="top">1062 (88.13)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Other</td><td align="left" valign="top">176 (11.54)</td><td align="left" valign="top">33 (10.31)</td><td align="left" valign="top">143 (11.87)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Primary language, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">&#x003E;.99</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>English</td><td align="left" valign="top">1464 (96)</td><td align="left" valign="top">307 (95.94)</td><td align="left" valign="top">1157 (96.02)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Other</td><td align="left" valign="top">61 (4)</td><td align="left" valign="top">13 (4.06)</td><td align="left" valign="top">48 (3.98)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top" colspan="2">Employment status, n (%)</td><td align="left" valign="top" colspan="2"/><td align="left" valign="top">.48</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Working</td><td align="left" valign="top">881 (57.77)</td><td align="left" valign="top">176 (55)</td><td align="left" valign="top">705 (58.51)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Student</td><td align="left" valign="top">43 (2.82)</td><td align="left" valign="top">10 (3.13)</td><td align="left" valign="top">33 (2.74)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Retired</td><td align="left" valign="top">370 (24.26)</td><td align="left" valign="top">87 (27.19)</td><td align="left" valign="top">283 (23.49)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Unemployed/ not working</td><td align="left" valign="top">154 (10.10)</td><td align="left" valign="top">28 (8.75)</td><td align="left" valign="top">126 (10.46)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Other</td><td align="left" valign="top">77 (5.05)</td><td align="left" valign="top">19 (5.94)</td><td align="left" valign="top">58 (4.81)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Sex, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">&#x003C;.001</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Male</td><td align="left" valign="top">734 (48.13)</td><td align="left" valign="top">187 (58.44)</td><td align="left" valign="top">547 (45.39)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Female</td><td align="left" valign="top">791 (51.87)</td><td align="left" valign="top">133 (41.56)</td><td align="left" valign="top">658 (54.61)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Religious, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">.33</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Yes</td><td align="left" valign="top">677 (44.39)</td><td align="left" valign="top">132 (41.25)</td><td align="left" valign="top">545 (45.22)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>No</td><td align="left" valign="top">778 (51.02)</td><td align="left" valign="top">170 (53.13)</td><td align="left" valign="top">608 (50.46)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Prefer not to say</td><td align="left" valign="top">70 (4.59)</td><td align="left" valign="top">18 (5.63)</td><td align="left" valign="top">52 (4.32)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top" colspan="2">Educational attainment, n (%)</td><td align="left" valign="top" colspan="2"/><td align="left" valign="top">&#x003C;.001</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Below degree level</td><td align="left" valign="top">747 (48.98)</td><td align="left" valign="top">193 (60.31)</td><td align="left" valign="top">554 (45.98)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Undergraduate degree</td><td align="left" valign="top">322 (21.11)</td><td align="left" valign="top">53 (16.56)</td><td align="left" valign="top">337 (27.97)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Postgraduate degree or higher</td><td align="left" valign="top">390 (25.57)</td><td align="left" valign="top">50 (15.63)</td><td align="left" valign="top">272 (22.57)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Don&#x2019;t know or prefer not to say</td><td align="left" valign="top">66 (4.33)</td><td align="left" valign="top">24 (7.50)</td><td align="left" valign="top">42 (3.49)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Social grade, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">&#x003C;.001</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>ABC1</td><td align="left" valign="top">809 (53.05)</td><td align="left" valign="top">138 (43.13)</td><td align="left" valign="top">671 (55.68)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>C2DE</td><td align="left" valign="top">716 (46.95)</td><td align="left" valign="top">182 (56.88)</td><td align="left" valign="top">534 (44.32)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top" colspan="2">Annual household income, n (%)</td><td align="left" valign="top" colspan="2"/><td align="left" valign="top">.001</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Less than &#x00A3;20,000</td><td align="left" valign="top">295 (19.34)</td><td align="left" valign="top">70 (21.88)</td><td align="left" valign="top">225 (18.67)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>&#x00A3;20,000&#x2013;&#x00A3;39,999</td><td align="left" valign="top">391 (25.64)</td><td align="left" valign="top">75 (23.44)</td><td align="left" valign="top">316 (26.22)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>&#x00A3;40,000&#x2013;&#x00A3;59,999</td><td align="left" valign="top">241 (15.80)</td><td align="left" valign="top">40 (12.50)</td><td align="left" valign="top">201 (16.68)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>&#x00A3;60,000 or greater</td><td align="left" valign="top">277 (18.16)</td><td align="left" valign="top">45 (14.06)</td><td align="left" valign="top">232 (19.25)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Prefer not to say</td><td align="left" valign="top">321 (21.05)</td><td align="left" valign="top">90 (28.13)</td><td align="left" valign="top">231 (19.17)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top" colspan="3">Frequency of meeting with family or friends, n (%)</td><td align="left" valign="top"/><td align="left" valign="top">.02</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Never or rarely</td><td align="left" valign="top">177 (11.61)</td><td align="left" valign="top">50 (15.63)</td><td align="left" valign="top">127 (10.54)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Weekly or monthly</td><td align="left" valign="top">970 (63.61)</td><td align="left" valign="top">203 (63.44)</td><td align="left" valign="top">767 (63.65)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Daily</td><td align="left" valign="top">378 (24.79)</td><td align="left" valign="top">67 (20.94)</td><td align="left" valign="top">311 (25.81)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Age group (years), n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">.02</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>18&#x2010;44</td><td align="left" valign="top">645 (42.30)</td><td align="left" valign="top">115 (35.94)</td><td align="left" valign="top">530 (43.98)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>45&#x2010;64</td><td align="left" valign="top">509 (33.38)</td><td align="left" valign="top">111 (34.69)</td><td align="left" valign="top">398 (33.03)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x2003;&#x2265;</named-content>65</td><td align="left" valign="top">371 (24.33)</td><td align="left" valign="top">94 (29.38)</td><td align="left" valign="top">277 (22.99)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Health condition, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">.005</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Yes</td><td align="left" valign="top">850 (55.74)</td><td align="left" valign="top">168 (52.50)</td><td align="left" valign="top">682 (56.60)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>No</td><td align="left" valign="top">599 (39.28)</td><td align="left" valign="top">125 (39.06)</td><td align="left" valign="top">474 (39.33)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Prefer not to say</td><td align="left" valign="top">76 (4.98)</td><td align="left" valign="top">27 (8.44)</td><td align="left" valign="top">49 (4.07)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top">0 (0)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top">Limited activity, n (%)</td><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top"/><td align="left" valign="top">&#x003C;.001</td></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Yes</td><td align="left" valign="top">432 (28.33)</td><td align="left" valign="top">89 (27.81)</td><td align="left" valign="top">343 (28.46)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>No</td><td align="left" valign="top">1058 (69.38)</td><td align="left" valign="top">212 (66.25)</td><td align="left" valign="top">846 (70.21)</td><td align="left" valign="top"/></tr><tr><td align="left" valign="top"><named-content content-type="indent">&#x00A0;&#x00A0;&#x00A0;&#x00A0;</named-content>Missing</td><td align="left" valign="top">35 (2.30)</td><td align="left" valign="top">19 (5.94)</td><td align="left" valign="top">16 (1.33)</td><td align="left" valign="top"/></tr></tbody></table><table-wrap-foot><fn id="table1fn1"><p><sup>a</sup>DHL: digital health literacy.</p></fn><fn id="table1fn2"><p><sup>b</sup><italic>P</italic> values reported in this table correspond to statistical tests of differences between low and high DHL groups. For continuous variables, <italic>P</italic> values were derived from Welch 2-sample <italic>t</italic> tests; for categorical variables, <italic>P</italic> values were derived from chi-square tests (or Fisher exact tests where expected cell count was &#x003C;5).</p></fn><fn id="table1fn3"><p><sup>c</sup>eHEALS: eHealth Literacy Scale.</p></fn><fn id="table1fn4"><p><sup>d</sup>Participants were asked &#x201C;Do you live in an urban, suburban, or rural area?&#x201D; with answer options urban, suburban, and rural; this variable was dichotomized to give urban and nonurban as groups.</p></fn></table-wrap-foot></table-wrap></sec><sec id="s3-2"><title>Assessment of DHL in the United Kingdom</title><p>Analysis indicated that eHEALS scores were not normally distributed (<xref ref-type="supplementary-material" rid="app3">Multimedia Appendix 3</xref>), as confirmed by the Shapiro-Wilk test (<italic>P</italic>&#x003C;.001). Median eHEALS was 31, with an IQR of 27&#x2010;32. The internal consistency of the data collected using eHEALS in this study was high (Cronbach &#x03B1;=0.93) and comparable with reliability estimates reported in previous studies [<xref ref-type="bibr" rid="ref21">21</xref>,<xref ref-type="bibr" rid="ref27">27</xref>,<xref ref-type="bibr" rid="ref28">28</xref>]. A fifth (320/1525, 21%) of the sample had a low level of DHL, based on the 26-point cutoff. Comparing the subpopulations with low and high levels of DHL, those with low DHL were more likely to be male, belong to an older age group, have a lower level of education, belong to a lower NRS social grade, and have a lower household income (<xref ref-type="table" rid="table1">Table 1</xref>). The eHEALS score IQR was wider among those with lower DHL, further indicating inequality in terms of the distribution of DHL in the UK population.</p><p>As shown in <xref ref-type="fig" rid="figure2">Figure 2</xref>, participants had the lowest level of agreement with &#x201C;I feel confident in using information from the Internet to make health decisions&#x201D; (Q8; 879/1525, 57.6%) and <italic>&#x201C;</italic>I can tell high quality from low quality health resources on the Internet&#x201D; (Q7; 847/1525, 55.5%).</p><fig position="float" id="figure2"><label>Figure 2.</label><caption><p>Participant responses to eHEALS items (N=1525). Response categories were grouped into agree (including &#x201C;strongly agree&#x201D; and &#x201C;agree&#x201D;), disagree (including &#x201C;strongly disagree&#x201D; and &#x201C;disagree&#x201D;), or neither. Q1: I know how to find helpful health resources on the internet; Q2: I know how to use the internet to answer my health questions; Q3: I know what health resources are available on the internet; Q4: I know where to find helpful health resources on the internet; Q5: I know how to use the health information I find on the internet to help me; Q6: I have the skills I need to evaluate the health resources I find on the internet; Q7: I can tell high quality from low quality health resources on the internet; and Q8: I feel confident in using information from the internet to make health decisions. eHEALS: eHealth Literacy Scale.</p></caption><graphic alt-version="no" mimetype="image" position="float" xlink:type="simple" xlink:href="jmir_v28i1e89136_fig02.png"/></fig></sec><sec id="s3-3"><title>Factors Associated With DHL</title><p>Univariable regression results are presented in <xref ref-type="supplementary-material" rid="app4">Multimedia Appendix 4</xref>. In the multivariable model based on the imputed dataset, age, social grade, sex, education, and frequency of meeting with family or friends were significant associates of DHL (<xref ref-type="fig" rid="figure3">Figure 3</xref>; <xref ref-type="supplementary-material" rid="app4">Multimedia Appendix 4</xref>). Those aged 65 years and older, compared with those in the age group of 18&#x2010;44 years, had significantly higher odds of low DHL (OR 1.43, 95% CI 1.02&#x2010;2.01; <italic>P</italic>=.04). Those belonging to the lower NRS social grade, C2DE, also had significantly higher odds of low DHL than those belonging to the higher social grade (OR 1.37, 95% CI 1.05&#x2010;1.80; <italic>P</italic>=.02). Those of female sex had lower odds of low DHL (OR 0.60, 95% CI 0.46&#x2010;0.77; <italic>P</italic>&#x003C;.001), as did those with an undergraduate or postgraduate degree or higher, compared with those educated to below degree level (undergraduate degree OR 0.52, 95% CI 0.37&#x2010;0.74, <italic>P</italic>&#x003C;.001; postgraduate degree or higher OR 0.58, 95% CI 0.40&#x2010;0.82, <italic>P</italic>=.002). Participants who reported meeting with family or friends daily, compared with those who reported they did this either never or rarely, had marginally significantly lower odds of low DHL (OR 0.64, 95% CI 0.42&#x2010;1.00; <italic>P</italic>=.05).</p><fig position="float" id="figure3"><label>Figure 3.</label><caption><p>Forest plot displaying sociodemographic, economic, and social associates of digital health literacy. Adjusted ORs and 95% CIs are shown. OR: odds ratio.</p></caption><graphic alt-version="no" mimetype="image" position="float" xlink:type="simple" xlink:href="jmir_v28i1e89136_fig03.png"/></fig></sec><sec id="s3-4"><title>Sensitivity Analyses</title><p>Among those participants with a health condition, female sex, being educated to undergraduate degree or postgraduate degree or greater, and meeting with family or friends daily continued to be statistically significant associates of DHL (<xref ref-type="supplementary-material" rid="app5">Multimedia Appendix 5</xref>). In this subgroup of participants, older age and lower social grade were no longer significantly associated with low DHL (age of 65 years and older OR 1.18, 95% CI 0.74&#x2010;1.88, <italic>P</italic>=.48; C2DE OR 1.41, 95% CI 0.97&#x2010;2.04, <italic>P</italic>=.07) (<xref ref-type="supplementary-material" rid="app5">Multimedia Appendix 5</xref>).</p><p>Using the median eHEALS score, 31, as an alternative cutoff produced results consistent with the primary analysis, with age of 65 years and older, social grade, sex, education, and frequency of meeting with family or friends remaining statistically significant associates of low DHL (<xref ref-type="supplementary-material" rid="app6">Multimedia Appendix 6</xref>). The direction of effect was consistent across both models, although the magnitude of associations differed slightly. Notably, the age group of 45&#x2010;64 years reached statistical significance in the median cutoff model (OR 1.38, 95% CI 1.07&#x2010;1.76; <italic>P</italic>=.01) (<xref ref-type="supplementary-material" rid="app6">Multimedia Appendix 6</xref>), suggesting that this is a borderline finding sensitive to the choice of threshold. Overall, these findings support the robustness of the primary findings.</p><p>Interaction terms were tested for 3 theoretically motivated pairs of predictors: age by sex, age by education, and sex by education (<xref ref-type="supplementary-material" rid="app7">Multimedia Appendix 7</xref>). All age by education and sex by education interaction terms were nonsignificant. One age by sex interaction term (female &#x00D7; age 45&#x2010;64 years) reached statistical significance (<italic>P</italic>=.009); however, the overall improvement in model fit was negligible [<xref ref-type="bibr" rid="ref54">54</xref>], with an AIC difference of 2 points between the interaction model and the primary model, based on a CCA approach. The primary model without interaction terms was therefore retained as the more parsimonious specification.</p><p>Results of the CCA are presented in <xref ref-type="supplementary-material" rid="app8">Multimedia Appendix 8</xref> to allow direct comparison of ORs and standard errors. The direction of effect was consistent across all variables between the 2 models. Coefficient estimates for the strongest sociodemographic, economic, and social associates of low DHL, including female sex, educational attainment, and older age, were attenuated in the imputed model compared with the CCA model, consistent with the systematic association between missingness and lower DHL scores identified in our missing data analysis. However, estimates for social grade C2DE and frequency of socializing were slightly larger in the imputed model, suggesting that the impact of missing data handling was variable across predictors. Notably, estimates for religion and age group of 45&#x2010;64 years were significant in the complete case model but not in the imputed model, while those for social grade C2DE and daily socializing reached significance in the imputed model but not in the complete case model. McFadden adjusted <italic>R</italic><sup>2</sup> for the CCA model was 0.06, indicating modest explanatory power of the included predictors. A likelihood ratio test comparing the null model with the fitted CCA model indicated a statistically significant improvement in model fit (<italic>&#x03C7;</italic><sup>2</sup><sub>12</sub>=80.15; <italic>P</italic>&#x003C;.001), suggesting that the predictors significantly improved the model&#x2019;s ability to explain variation in DHL level. The AIC was 1258.8.</p></sec></sec><sec id="s4" sec-type="discussion"><title>Discussion</title><sec id="s4-1"><title>Principal Findings</title><p>The median eHEALS score in this population was 31, which is defined as a high level of DHL. However, a fifth (320/1525, 21%) of the participants had a low level of DHL. Participant agreement was lowest regarding using internet-based information to make health decisions and distinguishing high- and low-quality health resources on the internet. Older participants, specifically those aged 65 years and older, and those in the lower social grade (C2DE) were more likely to have low DHL after adjustment. Conversely, female participants, those with greater educational attainment, and those who socialized with family and friends more frequently were less likely to have low DHL. No evidence of a significant association was found between DHL and urbanicity, ethnicity, religion, or limited activity.</p></sec><sec id="s4-2"><title>Comparison With Existing Literature</title><p>The median eHEALS score in this study was slightly higher relative to previous studies conducted in the United Kingdom [<xref ref-type="bibr" rid="ref32">32</xref>,<xref ref-type="bibr" rid="ref33">33</xref>,<xref ref-type="bibr" rid="ref55">55</xref>]. This study identified a lower proportion of participants with low DHL (320/1525, 21%) compared with previous studies, although this difference could be attributed to between-country differences in DHL [<xref ref-type="bibr" rid="ref32">32</xref>].</p><p>Despite the frequent use of eHEALS to measure DHL, relatively few studies report levels of agreement with individual scale items. However, among those studies that do report item-level breakdowns, there is consistency in which items receive the highest level of disagreement [<xref ref-type="bibr" rid="ref27">27</xref>,<xref ref-type="bibr" rid="ref56">56</xref>,<xref ref-type="bibr" rid="ref57">57</xref>]. These findings indicate that populations struggle when it comes to critically engaging with, assessing, and applying digital health information.</p><p>Regarding the significant associates of DHL, a summary of findings compared with the previous literature is presented in <xref ref-type="table" rid="table2">Table 2</xref>. The observed relationship between education and DHL in this study aligns with evidence highlighting education as one of the most consistent associates of eHEALS scores [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref33">33</xref>,<xref ref-type="bibr" rid="ref56">56</xref>].</p><table-wrap id="t2" position="float"><label>Table 2.</label><caption><p>Summary of findings, compared with the previous literature and mapped to the PROGRESS-Plus framework.</p></caption><table id="table2" frame="hsides" rules="groups"><thead><tr><td align="left" valign="bottom">Predictor variable</td><td align="left" valign="bottom">Summary of findings</td><td align="left" valign="bottom">Comparison with the literature</td></tr></thead><tbody><tr><td align="left" valign="top">Region</td><td align="left" valign="top">This study found no effect of UK region on DHL<sup><xref ref-type="table-fn" rid="table2fn1">a</xref></sup> in the unadjusted analysis.</td><td align="left" valign="top">To date, no studies have investigated the effect of UK region on DHL.</td></tr><tr><td align="left" valign="top">Urbanicity</td><td align="left" valign="top">This study found no effect of urbanicity on DHL in either unadjusted or adjusted analysis.</td><td align="left" valign="top">This is in line with a previous UK-based study [<xref ref-type="bibr" rid="ref33">33</xref>], although this remains an understudied variable with regard to DHL.</td></tr><tr><td align="left" valign="top">Ethnicity</td><td align="left" valign="top">This study found no effect of ethnicity on DHL in either unadjusted or adjusted analysis.</td><td align="left" valign="top">This supports previous evidence from 2 UK-based studies and an international review of the literature [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref32">32</xref>,<xref ref-type="bibr" rid="ref33">33</xref>].</td></tr><tr><td align="left" valign="top">Primary language</td><td align="left" valign="top">This study found no effect of primary language spoken on DHL in unadjusted analysis.</td><td align="left" valign="top">This supports findings from a US-based study, which included participants who primarily spoke Spanish at home [<xref ref-type="bibr" rid="ref58">58</xref>], but negates findings from Sweden, where Arabic-speaking participants were more likely to have low DHL [<xref ref-type="bibr" rid="ref34">34</xref>].</td></tr><tr><td align="left" valign="top">Employment status</td><td align="left" valign="top">This study found no effect of employment status on DHL in unadjusted analysis.</td><td align="left" valign="top">This broadly supports the evidence base [<xref ref-type="bibr" rid="ref10">10</xref>]. On the other hand, a study in China found that nonemployed participants had lower eHEALS<sup><xref ref-type="table-fn" rid="table2fn2">b</xref></sup> scores than their employed counterparts [<xref ref-type="bibr" rid="ref35">35</xref>].</td></tr><tr><td align="left" valign="top">Sex</td><td align="left" valign="top">Sex was associated with DHL in both unadjusted and adjusted analyses.</td><td align="left" valign="top">This contrasts with some previous literature, which reports mixed effects [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref32">32</xref>].</td></tr><tr><td align="left" valign="top">Religion</td><td align="left" valign="top">This study found no effect of religious self-identification on DHL in unadjusted or adjusted analysis.</td><td align="left" valign="top">To date, no studies have investigated the effect of religion on DHL.</td></tr><tr><td align="left" valign="top">Education</td><td align="left" valign="top">Education was associated with DHL in both unadjusted and adjusted analyses.</td><td align="left" valign="top">This supports previous evidence, including an international review of the literature [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref33">33</xref>].</td></tr><tr><td align="left" valign="top">Socioeconomic status</td><td align="left" valign="top">NRS<sup><xref ref-type="table-fn" rid="table2fn3">c</xref></sup> social grade was associated with DHL in both unadjusted and adjusted analyses. It was not associated with DHL among those participants with a chronic health condition.<break/>An annual income of &#x00A3;60,000 or greater was associated with DHL in unadjusted analysis.</td><td align="left" valign="top">Socioeconomic status is measured in many ways in the literature, making comparison challenging. When looking at income specifically, this has been found to be a determinant of eHEALS score [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref31">31</xref>].</td></tr><tr><td align="left" valign="top">Social support</td><td align="left" valign="top">Frequency of meetings with family or friends was associated with DHL in both unadjusted and adjusted analysis. This association was retained across sensitivity analysis using the median eHEALS value as a cutoff and among participants with a health condition. The association was nonsignificant in the CCA<sup><xref ref-type="table-fn" rid="table2fn4">d</xref></sup>.</td><td align="left" valign="top">Social support has been suggested as a determinant of DHL in a review [<xref ref-type="bibr" rid="ref10">10</xref>]. Although this is operationalized in different ways across studies, there is some indication that social support could be a protective factor to DHL [<xref ref-type="bibr" rid="ref35">35</xref>,<xref ref-type="bibr" rid="ref59">59</xref>].</td></tr><tr><td align="left" valign="top">Age (years)</td><td align="left" valign="top">Older age (65 years and older) was associated with DHL, in both unadjusted and adjusted analyses. It was not associated with DHL among those participants with a chronic health condition.<break/>Middle age (45&#x2010;64 years) is not a significant associate of low DHL in the primary analysis, although it reached significance in the sensitivity analysis that used the median eHEALS value as a cutoff. The interaction term female &#x00D7; 45&#x2010;64 years reached statistical significance.</td><td align="left" valign="top">This broadly supports previous evidence from 2 UK-based studies and 2 separate meta-analyses [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref31">31</xref>-<xref ref-type="bibr" rid="ref33">33</xref>]. The lack of effect among participants with a chronic health condition also supports previous findings [<xref ref-type="bibr" rid="ref56">56</xref>].</td></tr><tr><td align="left" valign="top">Chronic health conditions</td><td align="left" valign="top">This study found no effect of the presence of a health condition on DHL in unadjusted analysis.</td><td align="left" valign="top">This contrasts with findings from an international meta-analysis, which found that participants with existing disease or at a higher risk for disease had lower eHEALS scores [<xref ref-type="bibr" rid="ref31">31</xref>].</td></tr><tr><td align="left" valign="top">Limited activity</td><td align="left" valign="top">This study found no effect of limited activity on DHL in unadjusted or adjusted analysis.</td><td align="left" valign="top">To date, no studies have investigated the effect of limited activity on DHL.</td></tr></tbody></table><table-wrap-foot><fn id="table2fn1"><p><sup>a</sup>DHL: digital health literacy.</p></fn><fn id="table2fn2"><p><sup>b</sup>eHEALS: eHealth Literacy Scale.</p></fn><fn id="table2fn3"><p><sup>c</sup>NRS: National Readership Survey.</p></fn><fn id="table2fn4"><p><sup>d</sup>CCA: complete case analysis.</p></fn></table-wrap-foot></table-wrap><p>The finding that age is a statistically significant sociodemographic associate of DHL is also consistent with prior research [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref31">31</xref>-<xref ref-type="bibr" rid="ref33">33</xref>]. Qualitative research suggests that older adults may experience barriers relating to technological discomfort; lack of perceived advantage; concerns about privacy, security, and access; and lack of self-alignment with the imagined user [<xref ref-type="bibr" rid="ref60">60</xref>]. The association between age group of 65 years and older and low DHL was robust across all analyses, consistent with this body of literature. In contrast, the association between age group of 45&#x2010;64 years and low DHL was less consistent, showing sensitivity to the choice of eHEALS cutoff and a significant interaction term with female sex, despite the interaction model not offering a meaningful improvement in overall model fit. This pattern may suggest that the relationship between middle age and DHL is heterogeneous, potentially varying by sex, and warrants further investigation in future studies.</p><p>Notably, among participants with chronic health conditions, age was no longer a statistically significant sociodemographic associate of DHL across any age group. One possible explanation is that individuals living with health conditions may engage with online health information out of necessity regardless of age, as the personal relevance of seeking and applying health information is heightened by their health status. This is consistent with findings from Stellefson et al [<xref ref-type="bibr" rid="ref56">56</xref>], who reported that age was not a predictor of DHL among US patients with chronic obstructive pulmonary disease after adjusting for multiple covariates [<xref ref-type="bibr" rid="ref56">56</xref>]. Taken together, these findings point to important context-specific nuances whereby health necessity may override typical age-related patterns.</p><p>This study identified sex as a statistically significant sociodemographic associate of DHL, even after adjustment for covariates, and across sensitivity analyses. This finding contrasts with some previous research [<xref ref-type="bibr" rid="ref32">32</xref>]. However, other studies suggest a more complex picture, likely reflecting heterogeneity in both study populations and health system contexts [<xref ref-type="bibr" rid="ref10">10</xref>]. It is worth noting that eHEALS measures perceived confidence in using digital health information rather than objectively assessed skill, and this distinction may be relevant to interpreting the observed sex difference. Research has suggested that eHEALS assesses self-efficacy rather than real-world performance [<xref ref-type="bibr" rid="ref61">61</xref>], and a study comparing eHEALS scores with actual task performance concluded that its emphasis on self-perception means that it does not accurately predict performance [<xref ref-type="bibr" rid="ref21">21</xref>]. A cross-sectional study of UK university students found that eHEALS was significantly positively correlated with general self-efficacy [<xref ref-type="bibr" rid="ref55">55</xref>], further supporting this interpretation. Men and women may differ in health information-seeking behavior and self-efficacy reporting styles independently of actual digital competence, which could contribute to the observed sex difference. The broader behavioral evidence supports this interpretation; women have been shown to engage more frequently with digital health tools, with 64.4% of online consultations in Great Britain completed by female patients [<xref ref-type="bibr" rid="ref62">62</xref>], and a higher proportion of women than men reporting use of digital technology to support their health in a nationally representative Welsh survey (71% vs 65%) [<xref ref-type="bibr" rid="ref63">63</xref>]. This suggests that the sex difference observed in this study may partly reflect differential engagement with and confidence in digital health resources, rather than a straightforward difference in underlying digital skill.</p><p>In this study, urbanicity and ethnicity had no effect on DHL. This is consistent with previous studies, which also reported no significant relationship between these variables and eHEALS score [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref32">32</xref>,<xref ref-type="bibr" rid="ref33">33</xref>]. However, these findings should be interpreted with caution. The relatively low proportion of non-White participants may have limited the statistical power to detect an effect. Similarly, primary language had no effect on DHL, in contrast to findings among Arabic- and Swedish speakers in Sweden [<xref ref-type="bibr" rid="ref34">34</xref>]. However, the predominance of English as the primary language in the sample likely limited the ability to detect an effect. The frequency of meeting with family or friends was a statistically significant sociodemographic associate of DHL. Wider evidence regarding the role that social support plays in DHL remains inconclusive [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref35">35</xref>,<xref ref-type="bibr" rid="ref56">56</xref>].</p></sec><sec id="s4-3"><title>Strengths, Limitations, and Future Research</title><p>To our knowledge, this is the first study to comprehensively examine the sociodemographic, economic, and social factors associated with DHL in the United Kingdom. This study adopts an equity-oriented approach by incorporating a broad range of factors, including social support and aspects of cultural capital. The study benefits from a large sample that is broadly representative of the UK adult population. eHEALS is a widely used instrument that has been validated in previous research.</p><p>The principal limitation of this study is related to the purely online dissemination of the survey that inadvertently excluded individuals who do not use the internet. According to Ofcom in 2024 [<xref ref-type="bibr" rid="ref64">64</xref>], 5% of UK adults reported never accessing the internet either at home or elsewhere, and the same percentage reported having no internet access at home. While this represents a relatively small proportion of the population, those excluded by virtue of being offline are systematically more likely to have low DHL. Consequently, the reported prevalence of low DHL (21%) should be interpreted as a likely underestimate of the true prevalence in the general UK population, and findings are most applicable to UK internet users rather than the population as a whole. Additionally, the study was unlikely to capture the most socially excluded populations, who are known to face pronounced digital inequities [<xref ref-type="bibr" rid="ref65">65</xref>]. To mitigate the risk of bias, few exclusion criteria were employed. Future research should consider mixed-mode recruitment and survey dissemination strategies to reach those without internet access [<xref ref-type="bibr" rid="ref66">66</xref>], in order to better characterize DHL in the full UK population.</p><p>Furthermore, the study sample was not fully representative in terms of ethnicity or language. While 88% (1329/1525) of participants identified as White, this compares with 82% in the 2021 England and Wales Census [<xref ref-type="bibr" rid="ref67">67</xref>]. Because of small subgroup sizes, all non-White ethnic groups were grouped together, limiting the ability to examine between-group differences. Similarly, 96% (1464/1525) of the sample reported English as their primary language, compared with 91% in the Census [<xref ref-type="bibr" rid="ref68">68</xref>]. This could be due to the survey requiring participants to be English-speaking; future research could overcome this by translating the survey tool into a range of languages.</p><p>DHL was self-reported using eHEALS, which may not accurately reflect participants&#x2019; actual abilities [<xref ref-type="bibr" rid="ref14">14</xref>,<xref ref-type="bibr" rid="ref21">21</xref>]. In addition, eHEALS was created almost 20 years ago, and it may not fully capture newer forms of digital health technology [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref69">69</xref>]. Despite this, eHEALS remains the most frequently used tool to measure DHL [<xref ref-type="bibr" rid="ref10">10</xref>,<xref ref-type="bibr" rid="ref14">14</xref>,<xref ref-type="bibr" rid="ref30">30</xref>]. Future studies should aim to use an updated validated instrument [<xref ref-type="bibr" rid="ref70">70</xref>]. For instance, the HLS<sub>19</sub>-DIGI instrument considers a broader range of digital information sources and has recently been validated in 13 European countries [<xref ref-type="bibr" rid="ref71">71</xref>]. Performance-based tests could also be used as an objective assessment of DHL [<xref ref-type="bibr" rid="ref70">70</xref>,<xref ref-type="bibr" rid="ref72">72</xref>].</p><p>A further limitation relates to missing data. Little&#x2019;s MCAR test [<xref ref-type="bibr" rid="ref48">48</xref>] indicated that data were not MCAR, and missingness in education and disability status was associated with significantly lower DHL scores, suggesting a systematic relationship between missingness and the outcome. Multiple imputation was therefore used as the primary analytical approach, with CCA presented as a sensitivity analysis. While the direction of effect was consistent across both models, some differences in the significance of associations were observed. These differences highlight the sensitivity of borderline findings to the method of missing data handling, and results for religion and age group of 45&#x2010;64 years, as well as social grade and frequency of socializing, should be interpreted with caution. Although MICE is considered the preferred approach when the MCAR assumption is not met, it relies on the assumption that data are missing at random, which cannot be formally verified [<xref ref-type="bibr" rid="ref50">50</xref>,<xref ref-type="bibr" rid="ref73">73</xref>]; the possibility of data missing not at random cannot be excluded [<xref ref-type="bibr" rid="ref50">50</xref>,<xref ref-type="bibr" rid="ref73">73</xref>]. As descriptive analyses and prevalence estimates were conducted on the full sample, the reported prevalence of low DHL (21%) is not affected by missing data handling.</p><p>The dichotomization of eHEALS scores, while consistent with the existing literature, carries inherent limitations including potential loss of statistical power and the imposition of an artificial binary distinction. The cutoff of 26 was adopted to facilitate comparison with prior research, although its derivation is not fully documented in the original source [<xref ref-type="bibr" rid="ref45">45</xref>]. Sensitivity analysis using the median as an alternative cutoff supported the robustness of the primary findings with the direction of effect consistent across both models. However, the association between age group of 45&#x2010;64 years and low DHL was sensitive to the choice of threshold, reaching significance only in the median cutoff model, and should therefore be interpreted with caution.</p><p>The study&#x2019;s cross-sectional design limits any ability to draw causal inferences. Finally, although the regression model was statistically significant, it accounted for only 6% of the variability in DHL in the complete case model, leaving the majority of variance unexplained. As model fit statistics are not straightforwardly pooled after multiple imputation [<xref ref-type="bibr" rid="ref51">51</xref>,<xref ref-type="bibr" rid="ref74">74</xref>], this figure is reported for the complete case model only; however, the imputed model was similarly consistent with modest explanatory power. While the identified associations are reliable, the sociodemographic, economic, and social factors examined are not strong associates of DHL at the individual level, and the model should not be interpreted as a predictive tool. This is consistent with the broader literature, which suggests that DHL is a complex, multidimensional construct shaped by factors beyond sociodemographic characteristics alone. Unmeasured variables that could account for the remaining variance include access to mobile devices [<xref ref-type="bibr" rid="ref33">33</xref>], frequency of use of digital technologies [<xref ref-type="bibr" rid="ref31">31</xref>,<xref ref-type="bibr" rid="ref75">75</xref>], self-efficacy in using such tools [<xref ref-type="bibr" rid="ref55">55</xref>,<xref ref-type="bibr" rid="ref76">76</xref>], perceived importance, and perceived usefulness [<xref ref-type="bibr" rid="ref31">31</xref>]. Future research should seek to incorporate these dimensions to develop a more comprehensive explanatory model of DHL. A further dimension not captured in this study is trust in digital health information sources. Trust in digital health technologies has been shown to be influenced by impediments, such as limited accessibility, fear of data exploitation, and poor information quality, as well as enablers including ease of use, customizable design features, and privacy [<xref ref-type="bibr" rid="ref77">77</xref>]. Trust has been recognized as an important influence on digital health care use, adoption, acceptance, and usefulness [<xref ref-type="bibr" rid="ref78">78</xref>]. A full exploration of trust as a factor associated with DHL is beyond the scope of this study but represents an important avenue for future research.</p></sec><sec id="s4-4"><title>Implications for Practice and Policy</title><p>Evidence from this study and prior research suggests that DHL is unevenly distributed across the UK population. Therefore, rather than adopting a one-size-fits-all approach, the NHS, public health bodies, and local authorities should tailor communication, services, and interventions based on the DHL needs of different population groups.</p><p>Two complementary strategies can be implemented. First, individual DHL can be improved through educational programs, tailored to account for variation in DHL by age, education, socioeconomic status, and sex. Based on this study, content should focus on applying internet-based information to make health decisions and discerning health resource quality. In terms of delivery format, demonstrations, in-person workshops, and tutorials have the potential to motivate individuals to engage with digital technologies [<xref ref-type="bibr" rid="ref14">14</xref>]. Particularly among older adults, ongoing and iterative support is likely to be more effective than one-time instruction [<xref ref-type="bibr" rid="ref79">79</xref>]. Given the potential role of social support in determining DHL, interventions that involve community members or peers who have higher levels of DHL may have greater success [<xref ref-type="bibr" rid="ref14">14</xref>]. This study suggests that necessity-driven engagement among people with health conditions may attenuate age- and socioeconomic-related barriers. Therefore, chronic condition management pathways represent a potential entry point for DHL support. Integrating a brief DHL screening tool into routine intake processes for patients with chronic conditions, flagging those scoring below a threshold to receive tailored DHL support, could provide a scalable and targeted approach to identifying and supporting individuals with low DHL at a point of existing engagement with health services [<xref ref-type="bibr" rid="ref80">80</xref>].</p><p>Second, digital health solutions should be developed with user-centered, inclusive design principles. Solutions should be tailored toward anticipated users&#x2019; DHL levels, ideally using co-design processes that involve users with lower DHL [<xref ref-type="bibr" rid="ref32">32</xref>]. Digital health tools should prioritize content that is applicable to users&#x2019; day-to-day life, for example, by helping to inform health decisions. For older adults, adjusting the size of display icons, tailoring volume settings, and simplifying interfaces of digital tools and apps may improve usability [<xref ref-type="bibr" rid="ref32">32</xref>].</p><p>Finally, to best serve the needs of all population groups, regular and localized monitoring of DHL is essential. Identifying populations with lower levels of DHL would enable more responsive health planning and guide resource allocation, creating a more equitable health system.</p></sec><sec id="s4-5"><title>Conclusions</title><p>This study found that 21% of the UK population had a low level of DHL and revealed sex, educational attainment, socioeconomic status, age, and frequency of socializing as statistically significant associates of DHL. Those aged 65 years and older were more likely to have low DHL than younger participants when adjusting for other factors. Those in the lower social grade (C2DE) were more likely to have low DHL than those in the higher social grade. Those of female sex were less likely to have low DHL, as were those with an undergraduate or postgraduate degree or higher, compared with those educated to below degree level. Those who socialized with friends and family daily were less likely to have low DHL. The modest explanatory power of the model suggests that additional factors beyond those examined play an important role, and the identified associates should not be interpreted as strong individual-level predictors of DHL. Tailored educational interventions and user-centered digital health solutions can help address the uneven distribution of DHL across the UK population. Notably, subgroup analysis among those with chronic health conditions suggests that necessity-driven engagement with health information may attenuate age- and socioeconomic-related barriers among those living with chronic conditions. Intervention strategies should therefore be tailored to health status, with chronic condition management pathways representing a valuable opportunity to support DHL across age groups. The findings of this study echo concerns in the literature around the limited applicability of eHEALS in the current digital health environment [<xref ref-type="bibr" rid="ref21">21</xref>,<xref ref-type="bibr" rid="ref69">69</xref>,<xref ref-type="bibr" rid="ref70">70</xref>,<xref ref-type="bibr" rid="ref81">81</xref>]. The development of an updated measurement tool could support the identification of population subgroups with low DHL.</p></sec></sec></body><back><ack><p>The authors would like to thank Ms Kate Gosschalk and Ms Honor Gray at YouGov for delivery and management of the survey fieldwork. During manuscript revision, the generative artificial intelligence (AI) tool Claude by Anthropic (Anthropic; Claude [version Sonnet 4.6], large language model, 2025) was used to assist with refining responses to reviewer comments, revising manuscript text, and providing coding assistance for statistical analyses in R. All AI-assisted content was reviewed, revised, and approved by the authors, who take full responsibility for the accuracy and integrity of the published work.</p></ack><notes><sec><title>Funding</title><p>ALN, BH, and GG were supported by the National Institute for Health and Care Research (NIHR) Applied Research Collaboration Northwest London. ALN is additionally supported by the NIHR North West London Patient Safety Research Collaboration, with infrastructure support from the NIHR Imperial Biomedical Research Centre. The funder had no involvement in the study design, data collection, analysis, interpretation, or the writing of the manuscript. The views expressed in this publication are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.</p></sec><sec><title>Data Availability</title><p>The datasets generated and analyzed during this study are available from the corresponding author on reasonable request.</p></sec></notes><fn-group><fn fn-type="con"><p>Conceptualization: ALN, AM, BH, and GG (equal)</p><p>Data curation: AA</p><p>Formal analysis: HE-S (lead) and SS (supporting)</p><p>Funding acquisition: ALN, AE-O, and AA (equal)</p><p>Investigation: HE-S (lead) and SS (supporting)</p><p>Methodology: ALN, BH, and GG (equal)</p><p>Project administration: ALN</p><p>Resources: ALN, AM, BH, and GG (equal)</p><p>Supervision: ALN, AM, BH, and GG (equal)</p><p>Validation: SS</p><p>Visualization: HE-S</p><p>Writing &#x2013; original draft: HE-S</p><p>Writing &#x2013; review &#x0026; editing: AE-O, ALN, AM, BH, GG, HE-S, and SS (equal)</p></fn><fn fn-type="conflict"><p>HE-S currently works for the UK Health Security Agency, an executive agency sponsored by the Department of Health and Social Care; however, she did not hold this position at the time the study was conducted. BH works for eConsult Health Ltd, a provider of electronic consultations for National Health Service primary, secondary, and urgent or emergency care. SS, AA, AEO, GG, AM, and ALN have nothing to disclose.</p></fn></fn-group><glossary><title>Abbreviations</title><def-list><def-item><term id="abb1">AIC</term><def><p>Akaike Information Criterion</p></def></def-item><def-item><term id="abb2">CCA</term><def><p>complete case analysis</p></def></def-item><def-item><term id="abb3">DHL</term><def><p>digital health literacy</p></def></def-item><def-item><term id="abb4">eHEALS</term><def><p>eHealth Literacy Scale</p></def></def-item><def-item><term id="abb5">MCAR</term><def><p>missing completely at random</p></def></def-item><def-item><term id="abb6">MICE</term><def><p>multiple imputation by chained equations</p></def></def-item><def-item><term id="abb7">NHS</term><def><p>National Health Service</p></def></def-item><def-item><term id="abb8">NRS</term><def><p>National Readership Survey</p></def></def-item><def-item><term id="abb9">OR</term><def><p>odds ratio</p></def></def-item><def-item><term id="abb10">STROBE</term><def><p>Strengthening the Reporting of Observational Studies in Epidemiology</p></def></def-item></def-list></glossary><ref-list><title>References</title><ref id="ref1"><label>1</label><nlm-citation citation-type="web"><article-title>Digital health</article-title><source>World Health Organization Regional Office for Europe</source><year>2025</year><access-date>2025-05-13</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.who.int/europe/health-topics/digital-health#tab=tab_1">https://www.who.int/europe/health-topics/digital-health#tab=tab_1</ext-link></comment></nlm-citation></ref><ref id="ref2"><label>2</label><nlm-citation citation-type="web"><article-title>Digital inclusion in health and care</article-title><source>Good Things Foundation</source><year>2020</year><access-date>2025-05-23</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.goodthingsfoundation.org/policy-and-research/research-and-evidence/research-2024/health-and-care-digital-inclusion.html">https://www.goodthingsfoundation.org/policy-and-research/research-and-evidence/research-2024/health-and-care-digital-inclusion.html</ext-link></comment></nlm-citation></ref><ref id="ref3"><label>3</label><nlm-citation citation-type="web"><article-title>Digital transformation</article-title><source>The National Archives</source><year>2019</year><access-date>2025-05-13</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.longtermplan.nhs.uk/areas-of-work/digital-transformation/">https://www.longtermplan.nhs.uk/areas-of-work/digital-transformation/</ext-link></comment></nlm-citation></ref><ref id="ref4"><label>4</label><nlm-citation citation-type="web"><article-title>Fit for the future: 10 year health plan for England</article-title><source>NHS England</source><year>2025</year><access-date>2025-07-28</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.england.nhs.uk/long-term-plan/">https://www.england.nhs.uk/long-term-plan/</ext-link></comment></nlm-citation></ref><ref id="ref5"><label>5</label><nlm-citation citation-type="web"><article-title>Independent investigation of the NHS in England</article-title><source>GOV.UK</source><year>2024</year><access-date>2025-07-28</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.gov.uk/government/publications/independent-investigation-of-the-nhs-in-england">https://www.gov.uk/government/publications/independent-investigation-of-the-nhs-in-england</ext-link></comment></nlm-citation></ref><ref id="ref6"><label>6</label><nlm-citation citation-type="web"><article-title>Talking points about health literacy</article-title><source>United States Centers for Disease Control and Prevention (CDC)</source><year>2024</year><access-date>2026-04-15</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.cdc.gov/health-literacy/php/about/tell-others.html">https://www.cdc.gov/health-literacy/php/about/tell-others.html</ext-link></comment></nlm-citation></ref><ref id="ref7"><label>7</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Shao</surname><given-names>Y</given-names> </name><name name-style="western"><surname>Hu</surname><given-names>H</given-names> </name><name name-style="western"><surname>Liang</surname><given-names>Y</given-names> </name><etal/></person-group><article-title>Health literacy interventions among patients with chronic diseases: a meta-analysis of randomized controlled trials</article-title><source>Patient Educ Couns</source><year>2023</year><month>09</month><volume>114</volume><fpage>107829</fpage><pub-id pub-id-type="doi">10.1016/j.pec.2023.107829</pub-id><pub-id pub-id-type="medline">37270933</pub-id></nlm-citation></ref><ref id="ref8"><label>8</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Nutbeam</surname><given-names>D</given-names> </name></person-group><article-title>Health literacy as a public health goal: a challenge for contemporary health education and communication strategies into the 21st century</article-title><source>Health Promot Int</source><year>2000</year><month>09</month><day>1</day><volume>15</volume><issue>3</issue><fpage>259</fpage><lpage>267</lpage><pub-id pub-id-type="doi">10.1093/heapro/15.3.259</pub-id></nlm-citation></ref><ref id="ref9"><label>9</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>S&#x00F8;rensen</surname><given-names>K</given-names> </name><name name-style="western"><surname>Van den Broucke</surname><given-names>S</given-names> </name><name name-style="western"><surname>Fullam</surname><given-names>J</given-names> </name><etal/></person-group><article-title>Health literacy and public health: a systematic review and integration of definitions and models</article-title><source>BMC Public Health</source><year>2012</year><month>01</month><day>25</day><volume>12</volume><fpage>1</fpage><lpage>13</lpage><pub-id pub-id-type="doi">10.1186/1471-2458-12-80</pub-id><pub-id pub-id-type="medline">22276600</pub-id></nlm-citation></ref><ref id="ref10"><label>10</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Estrela</surname><given-names>M</given-names> </name><name name-style="western"><surname>Semedo</surname><given-names>G</given-names> </name><name name-style="western"><surname>Roque</surname><given-names>F</given-names> </name><name name-style="western"><surname>Ferreira</surname><given-names>PL</given-names> </name><name name-style="western"><surname>Herdeiro</surname><given-names>MT</given-names> </name></person-group><article-title>Sociodemographic determinants of digital health literacy: a systematic review and meta-analysis</article-title><source>Int J Med Inform</source><year>2023</year><month>09</month><volume>177</volume><fpage>105124</fpage><pub-id pub-id-type="doi">10.1016/j.ijmedinf.2023.105124</pub-id><pub-id pub-id-type="medline">37329766</pub-id></nlm-citation></ref><ref id="ref11"><label>11</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>van Kessel</surname><given-names>R</given-names> </name><name name-style="western"><surname>Wong</surname><given-names>BLH</given-names> </name><name name-style="western"><surname>Clemens</surname><given-names>T</given-names> </name><name name-style="western"><surname>Brand</surname><given-names>H</given-names> </name></person-group><article-title>Digital health literacy as a super determinant of health: More than simply the sum of its parts</article-title><source>Internet Interv</source><year>2022</year><month>03</month><volume>27</volume><fpage>100500</fpage><pub-id pub-id-type="doi">10.1016/j.invent.2022.100500</pub-id><pub-id pub-id-type="medline">35242586</pub-id></nlm-citation></ref><ref id="ref12"><label>12</label><nlm-citation citation-type="book"><person-group person-group-type="author"><collab>World Health Organization Regional Office for Europe</collab></person-group><source>Digital Health in the WHO European Region: The Ongoing Journey to Commitment and Transformation</source><year>2023</year><access-date>2025-05-09</access-date><publisher-name>World Health Organization</publisher-name><comment><ext-link ext-link-type="uri" xlink:href="https://www.who.int/europe/publications/m/item/digital-health-in-the-who-european-region-the-ongoing-journey-to-commitment-and-transformation">https://www.who.int/europe/publications/m/item/digital-health-in-the-who-european-region-the-ongoing-journey-to-commitment-and-transformation</ext-link></comment></nlm-citation></ref><ref id="ref13"><label>13</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Mukhtar</surname><given-names>T</given-names> </name><name name-style="western"><surname>Babur</surname><given-names>MN</given-names> </name><name name-style="western"><surname>Abbas</surname><given-names>R</given-names> </name><name name-style="western"><surname>Irshad</surname><given-names>A</given-names> </name><name name-style="western"><surname>Kiran</surname><given-names>Q</given-names> </name></person-group><article-title>Digital Health Literacy: a systematic review of interventions and their influence on healthcare access and sustainable development Goal-3 (SDG-3)</article-title><source>Pak J Med Sci</source><year>2025</year><month>03</month><volume>41</volume><issue>3</issue><fpage>910</fpage><lpage>918</lpage><pub-id pub-id-type="doi">10.12669/pjms.41.3.10639</pub-id><pub-id pub-id-type="medline">40103887</pub-id></nlm-citation></ref><ref id="ref14"><label>14</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Arias L&#x00F3;pez</surname><given-names>M del P</given-names> </name><name name-style="western"><surname>Ong</surname><given-names>BA</given-names> </name><name name-style="western"><surname>Borrat Frigola</surname><given-names>X</given-names> </name><etal/></person-group><article-title>Digital literacy as a new determinant of health: a scoping review</article-title><source>PLoS Digit Health</source><year>2023</year><volume>2</volume><issue>10</issue><fpage>e0000279</fpage><pub-id pub-id-type="doi">10.1371/journal.pdig.0000279</pub-id></nlm-citation></ref><ref id="ref15"><label>15</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Neter</surname><given-names>E</given-names> </name><name name-style="western"><surname>Brainin</surname><given-names>E</given-names> </name></person-group><article-title>eHealth literacy: extending the digital divide to the realm of health information</article-title><source>J Med Internet Res</source><year>2012</year><month>01</month><day>27</day><volume>14</volume><issue>1</issue><fpage>e19</fpage><pub-id pub-id-type="doi">10.2196/jmir.1619</pub-id><pub-id pub-id-type="medline">22357448</pub-id></nlm-citation></ref><ref id="ref16"><label>16</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>van Deursen</surname><given-names>A</given-names> </name><name name-style="western"><surname>van Dijk</surname><given-names>J</given-names> </name></person-group><article-title>Internet skills performance tests: are people ready for eHealth?</article-title><source>J Med Internet Res</source><year>2011</year><month>04</month><day>29</day><volume>13</volume><issue>2</issue><fpage>e35</fpage><pub-id pub-id-type="doi">10.2196/jmir.1581</pub-id><pub-id pub-id-type="medline">21531690</pub-id></nlm-citation></ref><ref id="ref17"><label>17</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Vicente</surname><given-names>MR</given-names> </name><name name-style="western"><surname>Madden</surname><given-names>G</given-names> </name></person-group><article-title>Assessing eHealth skills across Europeans</article-title><source>Health Policy Technol</source><year>2017</year><month>06</month><volume>6</volume><issue>2</issue><fpage>161</fpage><lpage>168</lpage><pub-id pub-id-type="doi">10.1016/j.hlpt.2017.04.001</pub-id></nlm-citation></ref><ref id="ref18"><label>18</label><nlm-citation citation-type="book"><person-group person-group-type="author"><name name-style="western"><surname>Aldridge</surname><given-names>S</given-names> </name></person-group><source>Improving Digital Health Inclusion: Evidence Scan</source><year>2020</year><access-date>2025-05-13</access-date><publisher-name>The Strategy Unit</publisher-name><comment><ext-link ext-link-type="uri" xlink:href="https://www.strategyunitwm.nhs.uk/sites/default/files/2021-04/Digital%20Inclusion%20evidence%20scan.pdf">https://www.strategyunitwm.nhs.uk/sites/default/files/2021-04/Digital%20Inclusion%20evidence%20scan.pdf</ext-link></comment></nlm-citation></ref><ref id="ref19"><label>19</label><nlm-citation citation-type="web"><article-title>National disability strategy</article-title><source>GOV.UK</source><year>2021</year><access-date>2026-06-16</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.gov.uk/government/publications/national-disability-strategy">https://www.gov.uk/government/publications/national-disability-strategy</ext-link></comment></nlm-citation></ref><ref id="ref20"><label>20</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Norman</surname><given-names>CD</given-names> </name><name name-style="western"><surname>Skinner</surname><given-names>HA</given-names> </name></person-group><article-title>eHealth literacy: essential skills for consumer health in a networked world</article-title><source>J Med Internet Res</source><year>2006</year><month>06</month><day>16</day><volume>8</volume><issue>2</issue><fpage>e9</fpage><pub-id pub-id-type="doi">10.2196/jmir.8.2.e9</pub-id><pub-id pub-id-type="medline">16867972</pub-id></nlm-citation></ref><ref id="ref21"><label>21</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>van der Vaart</surname><given-names>R</given-names> </name><name name-style="western"><surname>van Deursen</surname><given-names>AJ</given-names> </name><name name-style="western"><surname>Drossaert</surname><given-names>CH</given-names> </name><name name-style="western"><surname>Taal</surname><given-names>E</given-names> </name><name name-style="western"><surname>van Dijk</surname><given-names>JA</given-names> </name><name name-style="western"><surname>van de Laar</surname><given-names>MA</given-names> </name></person-group><article-title>Does the eHealth Literacy Scale (eHEALS) measure what it intends to measure? Validation of a Dutch version of the eHEALS in two adult populations</article-title><source>J Med Internet Res</source><year>2011</year><volume>13</volume><issue>4</issue><fpage>e86</fpage><pub-id pub-id-type="doi">10.2196/jmir.1840</pub-id></nlm-citation></ref><ref id="ref22"><label>22</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Soellner</surname><given-names>R</given-names> </name><name name-style="western"><surname>Huber</surname><given-names>S</given-names> </name><name name-style="western"><surname>Reder</surname><given-names>M</given-names> </name></person-group><article-title>The concept of eHealth literacy and its measurement</article-title><source>J Media Psychol</source><year>2014</year><month>01</month><volume>26</volume><issue>1</issue><fpage>29</fpage><lpage>38</lpage><pub-id pub-id-type="doi">10.1027/1864-1105/a000104</pub-id></nlm-citation></ref><ref id="ref23"><label>23</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Abdulai</surname><given-names>AF</given-names> </name><name name-style="western"><surname>Tiffere</surname><given-names>AH</given-names> </name><name name-style="western"><surname>Adam</surname><given-names>F</given-names> </name><name name-style="western"><surname>Kabanunye</surname><given-names>MM</given-names> </name></person-group><article-title>COVID-19 information-related digital literacy among online health consumers in a low-income country</article-title><source>Int J Med Inform</source><year>2021</year><month>01</month><volume>145</volume><fpage>104322</fpage><pub-id pub-id-type="doi">10.1016/j.ijmedinf.2020.104322</pub-id><pub-id pub-id-type="medline">33157342</pub-id></nlm-citation></ref><ref id="ref24"><label>24</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Choi</surname><given-names>NG</given-names> </name><name name-style="western"><surname>Dinitto</surname><given-names>DM</given-names> </name></person-group><article-title>The digital divide among low-income homebound older adults: Internet use patterns, eHealth literacy, and attitudes toward computer/Internet use</article-title><source>J Med Internet Res</source><year>2013</year><month>05</month><day>2</day><volume>15</volume><issue>5</issue><fpage>e93</fpage><pub-id pub-id-type="doi">10.2196/jmir.2645</pub-id><pub-id pub-id-type="medline">23639979</pub-id></nlm-citation></ref><ref id="ref25"><label>25</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Hsu</surname><given-names>W</given-names> </name><name name-style="western"><surname>Chiang</surname><given-names>C</given-names> </name><name name-style="western"><surname>Yang</surname><given-names>S</given-names> </name></person-group><article-title>The effect of individual factors on health behaviors among college students: the mediating effects of eHealth literacy</article-title><source>J Med Internet Res</source><year>2014</year><month>12</month><day>12</day><volume>16</volume><issue>12</issue><fpage>e287</fpage><pub-id pub-id-type="doi">10.2196/jmir.3542</pub-id><pub-id pub-id-type="medline">25499086</pub-id></nlm-citation></ref><ref id="ref26"><label>26</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Choi</surname><given-names>N</given-names> </name></person-group><article-title>Relationship between health service use and health information technology use among older adults: analysis of the US National Health Interview Survey</article-title><source>J Med Internet Res</source><year>2011</year><month>04</month><day>20</day><volume>13</volume><issue>2</issue><fpage>e33</fpage><pub-id pub-id-type="doi">10.2196/jmir.1753</pub-id><pub-id pub-id-type="medline">21752784</pub-id></nlm-citation></ref><ref id="ref27"><label>27</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Tennant</surname><given-names>B</given-names> </name><name name-style="western"><surname>Stellefson</surname><given-names>M</given-names> </name><name name-style="western"><surname>Dodd</surname><given-names>V</given-names> </name><etal/></person-group><article-title>eHealth literacy and Web 2.0 health information seeking behaviors among baby boomers and older adults</article-title><source>J Med Internet Res</source><year>2015</year><month>03</month><day>17</day><volume>17</volume><issue>3</issue><fpage>e70</fpage><pub-id pub-id-type="doi">10.2196/jmir.3992</pub-id><pub-id pub-id-type="medline">25783036</pub-id></nlm-citation></ref><ref id="ref28"><label>28</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Norman</surname><given-names>CD</given-names> </name><name name-style="western"><surname>Skinner</surname><given-names>HA</given-names> </name></person-group><article-title>eHEALS: The eHealth Literacy Scale</article-title><source>J Med Internet Res</source><year>2006</year><month>11</month><day>14</day><volume>8</volume><issue>4</issue><fpage>e27</fpage><pub-id pub-id-type="doi">10.2196/jmir.8.4.e27</pub-id><pub-id pub-id-type="medline">17213046</pub-id></nlm-citation></ref><ref id="ref29"><label>29</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Sudbury-Riley</surname><given-names>L</given-names> </name><name name-style="western"><surname>FitzPatrick</surname><given-names>M</given-names> </name><name name-style="western"><surname>Schulz</surname><given-names>PJ</given-names> </name></person-group><article-title>Exploring the measurement properties of the eHealth Literacy Scale (eHEALS) among baby boomers: a multinational test of measurement invariance</article-title><source>J Med Internet Res</source><year>2017</year><month>02</month><day>27</day><volume>19</volume><issue>2</issue><fpage>e53</fpage><pub-id pub-id-type="doi">10.2196/jmir.5998</pub-id><pub-id pub-id-type="medline">28242590</pub-id></nlm-citation></ref><ref id="ref30"><label>30</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Paige</surname><given-names>SR</given-names> </name><name name-style="western"><surname>Miller</surname><given-names>MD</given-names> </name><name name-style="western"><surname>Krieger</surname><given-names>JL</given-names> </name><name name-style="western"><surname>Stellefson</surname><given-names>M</given-names> </name><name name-style="western"><surname>Cheong</surname><given-names>J</given-names> </name></person-group><article-title>Electronic health literacy across the lifespan: measurement invariance study</article-title><source>J Med Internet Res</source><year>2018</year><month>07</month><day>9</day><volume>20</volume><issue>7</issue><fpage>e10434</fpage><pub-id pub-id-type="doi">10.2196/10434</pub-id><pub-id pub-id-type="medline">29986848</pub-id></nlm-citation></ref><ref id="ref31"><label>31</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Hua</surname><given-names>Z</given-names> </name><name name-style="western"><surname>Yuqing</surname><given-names>S</given-names> </name><name name-style="western"><surname>Qianwen</surname><given-names>L</given-names> </name><name name-style="western"><surname>Hong</surname><given-names>C</given-names> </name></person-group><article-title>Factors influencing eHealth literacy worldwide: systematic review and meta-analysis</article-title><source>J Med Internet Res</source><year>2025</year><month>03</month><day>10</day><volume>27</volume><fpage>e50313</fpage><pub-id pub-id-type="doi">10.2196/50313</pub-id><pub-id pub-id-type="medline">40063939</pub-id></nlm-citation></ref><ref id="ref32"><label>32</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Qiu</surname><given-names>CS</given-names> </name><name name-style="western"><surname>Lunova</surname><given-names>T</given-names> </name><name name-style="western"><surname>Greenfield</surname><given-names>G</given-names> </name><etal/></person-group><article-title>Determinants of digital health literacy: international cross-sectional study</article-title><source>J Med Internet Res</source><year>2025</year><volume>27</volume><fpage>e66631</fpage><pub-id pub-id-type="doi">10.2196/66631</pub-id></nlm-citation></ref><ref id="ref33"><label>33</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Moon</surname><given-names>Z</given-names> </name><name name-style="western"><surname>Zuchowski</surname><given-names>M</given-names> </name><name name-style="western"><surname>Moss-Morris</surname><given-names>R</given-names> </name><name name-style="western"><surname>Hunter</surname><given-names>MS</given-names> </name><name name-style="western"><surname>Norton</surname><given-names>S</given-names> </name><name name-style="western"><surname>Hughes</surname><given-names>LD</given-names> </name></person-group><article-title>Disparities in access to mobile devices and e-Health literacy among breast cancer survivors</article-title><source>Support Care Cancer</source><year>2022</year><month>01</month><volume>30</volume><issue>1</issue><fpage>117</fpage><lpage>126</lpage><pub-id pub-id-type="doi">10.1007/s00520-021-06407-2</pub-id><pub-id pub-id-type="medline">34236506</pub-id></nlm-citation></ref><ref id="ref34"><label>34</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Bergman</surname><given-names>L</given-names> </name><name name-style="western"><surname>Nilsson</surname><given-names>U</given-names> </name><name name-style="western"><surname>Dahlberg</surname><given-names>K</given-names> </name><name name-style="western"><surname>Jaensson</surname><given-names>M</given-names> </name><name name-style="western"><surname>W&#x00E5;ngdahl</surname><given-names>J</given-names> </name></person-group><article-title>Health literacy and e-Health literacy among Arabic-speaking migrants in Sweden: a cross-sectional study</article-title><source>BMC Public Health</source><year>2021</year><month>11</month><day>25</day><volume>21</volume><issue>1</issue><fpage>2165</fpage><pub-id pub-id-type="doi">10.1186/s12889-021-12187-5</pub-id><pub-id pub-id-type="medline">34823499</pub-id></nlm-citation></ref><ref id="ref35"><label>35</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Xu</surname><given-names>RH</given-names> </name><name name-style="western"><surname>Zhou</surname><given-names>LM</given-names> </name><name name-style="western"><surname>Wong</surname><given-names>ELY</given-names> </name><name name-style="western"><surname>Wang</surname><given-names>D</given-names> </name></person-group><article-title>The association between patients&#x2019; eHealth literacy and satisfaction with shared decision-making and well-being: multicenter cross-sectional study</article-title><source>J Med Internet Res</source><year>2021</year><month>09</month><day>24</day><volume>23</volume><issue>9</issue><fpage>e26721</fpage><pub-id pub-id-type="doi">10.2196/26721</pub-id><pub-id pub-id-type="medline">34559062</pub-id></nlm-citation></ref><ref id="ref36"><label>36</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Nguyet</surname><given-names>NB</given-names> </name><name name-style="western"><surname>Tam</surname><given-names>NT</given-names> </name><name name-style="western"><surname>Huong</surname><given-names>NTL</given-names> </name><name name-style="western"><surname>Cuong</surname><given-names>NT</given-names> </name><name name-style="western"><surname>Van</surname><given-names>BTT</given-names> </name><name name-style="western"><surname>Thang</surname><given-names>TQ</given-names> </name></person-group><article-title>Health and eHealth literacy in Vietnam: evidence from a national survey</article-title><source>Patient Educ Couns</source><year>2026</year><month>07</month><volume>148</volume><fpage>109583</fpage><pub-id pub-id-type="doi">10.1016/j.pec.2026.109583</pub-id></nlm-citation></ref><ref id="ref37"><label>37</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>von Elm</surname><given-names>E</given-names> </name><name name-style="western"><surname>Altman</surname><given-names>DG</given-names> </name><name name-style="western"><surname>Egger</surname><given-names>M</given-names> </name><etal/></person-group><article-title>The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies</article-title><source>J Clin Epidemiol</source><year>2008</year><month>04</month><volume>61</volume><issue>4</issue><fpage>344</fpage><lpage>349</lpage><pub-id pub-id-type="doi">10.1016/j.jclinepi.2007.11.008</pub-id><pub-id pub-id-type="medline">18313558</pub-id></nlm-citation></ref><ref id="ref38"><label>38</label><nlm-citation citation-type="web"><article-title>YouGov member terms and conditions</article-title><source>YouGov</source><year>2025</year><access-date>2025-08-08</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://account.yougov.com/gb-en/account/terms-and-conditions">https://account.yougov.com/gb-en/account/terms-and-conditions</ext-link></comment></nlm-citation></ref><ref id="ref39"><label>39</label><nlm-citation citation-type="web"><article-title>Privacy policy</article-title><source>YouGov</source><year>2025</year><access-date>2025-08-08</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://account.yougov.com/gb-en/account/privacy-policy">https://account.yougov.com/gb-en/account/privacy-policy</ext-link></comment></nlm-citation></ref><ref id="ref40"><label>40</label><nlm-citation citation-type="web"><article-title>Approximated social grade data</article-title><source>Office for National Statistics</source><year>2023</year><month>08</month><day>17</day><access-date>2026-06-30</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.ons.gov.uk/census/aboutcensus/censusproducts/approximatedsocialgradedata">https://www.ons.gov.uk/census/aboutcensus/censusproducts/approximatedsocialgradedata</ext-link></comment></nlm-citation></ref><ref id="ref41"><label>41</label><nlm-citation citation-type="web"><article-title>Principal projection&#x2014;UK population in age groups</article-title><source>Office for National Statistics</source><year>2024</year><access-date>2025-06-06</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationprojections/datasets/tablea21principalprojectionukpopulationinagegroups">https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationprojections/datasets/tablea21principalprojectionukpopulationinagegroups</ext-link></comment></nlm-citation></ref><ref id="ref42"><label>42</label><nlm-citation citation-type="web"><article-title>PROGRESS-Plus</article-title><source>Cochrane Methods: Equity</source><year>2025</year><access-date>2025-05-21</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://methods.cochrane.org/equity/projects/evidence-equity/progress-plus">https://methods.cochrane.org/equity/projects/evidence-equity/progress-plus</ext-link></comment></nlm-citation></ref><ref id="ref43"><label>43</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>O&#x2019;Neill</surname><given-names>J</given-names> </name><name name-style="western"><surname>Tabish</surname><given-names>H</given-names> </name><name name-style="western"><surname>Welch</surname><given-names>V</given-names> </name><etal/></person-group><article-title>Applying an equity lens to interventions: using PROGRESS ensures consideration of socially stratifying factors to illuminate inequities in health</article-title><source>J Clin Epidemiol</source><year>2014</year><month>01</month><volume>67</volume><issue>1</issue><fpage>56</fpage><lpage>64</lpage><pub-id pub-id-type="doi">10.1016/j.jclinepi.2013.08.005</pub-id><pub-id pub-id-type="medline">24189091</pub-id></nlm-citation></ref><ref id="ref44"><label>44</label><nlm-citation citation-type="web"><article-title>WMA Declaration of Helsinki&#x2013;ethical principles for medical research involving human participants</article-title><source>WMA&#x2013;World Medical Association</source><year>2024</year><access-date>2025-06-09</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.wma.net/policies-post/wma-declaration-of-helsinki/">https://www.wma.net/policies-post/wma-declaration-of-helsinki/</ext-link></comment></nlm-citation></ref><ref id="ref45"><label>45</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Richtering</surname><given-names>SS</given-names> </name><name name-style="western"><surname>Hyun</surname><given-names>K</given-names> </name><name name-style="western"><surname>Neubeck</surname><given-names>L</given-names> </name><etal/></person-group><article-title>eHealth literacy: predictors in a population with moderate-to-high cardiovascular risk</article-title><source>JMIR Hum Factors</source><year>2017</year><month>01</month><day>27</day><volume>4</volume><issue>1</issue><fpage>e4</fpage><pub-id pub-id-type="doi">10.2196/humanfactors.6217</pub-id><pub-id pub-id-type="medline">28130203</pub-id></nlm-citation></ref><ref id="ref46"><label>46</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Cherid</surname><given-names>C</given-names> </name><name name-style="western"><surname>Baghdadli</surname><given-names>A</given-names> </name><name name-style="western"><surname>Wall</surname><given-names>M</given-names> </name><etal/></person-group><article-title>Current level of technology use, health and eHealth literacy in older Canadians with a recent fracture-a survey in orthopedic clinics</article-title><source>Osteoporos Int</source><year>2020</year><month>07</month><volume>31</volume><issue>7</issue><fpage>1333</fpage><lpage>1340</lpage><pub-id pub-id-type="doi">10.1007/s00198-020-05359-3</pub-id><pub-id pub-id-type="medline">32112118</pub-id></nlm-citation></ref><ref id="ref47"><label>47</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Lee</surname><given-names>WL</given-names> </name><name name-style="western"><surname>Lim</surname><given-names>ZJ</given-names> </name><name name-style="western"><surname>Tang</surname><given-names>LY</given-names> </name><name name-style="western"><surname>Yahya</surname><given-names>NA</given-names> </name><name name-style="western"><surname>Varathan</surname><given-names>KD</given-names> </name><name name-style="western"><surname>Ludin</surname><given-names>SM</given-names> </name></person-group><article-title>Patients&#x2019; technology readiness and eHealth literacy: implications for adoption and deployment of eHealth in the COVID-19 era and beyond</article-title><source>Comput Inform Nurs</source><year>2021</year><month>11</month><day>2</day><volume>40</volume><issue>4</issue><fpage>244</fpage><lpage>250</lpage><pub-id pub-id-type="doi">10.1097/CIN.0000000000000854</pub-id><pub-id pub-id-type="medline">34740221</pub-id></nlm-citation></ref><ref id="ref48"><label>48</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Little</surname><given-names>RJA</given-names> </name></person-group><article-title>A test of missing completely at random for multivariate data with missing values</article-title><source>J Am Stat Assoc</source><year>1988</year><month>12</month><volume>83</volume><issue>404</issue><fpage>1198</fpage><lpage>1202</lpage><pub-id pub-id-type="doi">10.1080/01621459.1988.10478722</pub-id></nlm-citation></ref><ref id="ref49"><label>49</label><nlm-citation citation-type="book"><person-group person-group-type="author"><name name-style="western"><surname>Rubin</surname><given-names>DB</given-names> </name></person-group><source>Multiple Imputation for Nonresponse in Surveys</source><year>1987</year><publisher-name>John Wiley &#x0026; Sons</publisher-name><comment><ext-link ext-link-type="uri" xlink:href="https://onlinelibrary.wiley.com/doi/book/10.1002/9780470316696">https://onlinelibrary.wiley.com/doi/book/10.1002/9780470316696</ext-link></comment><pub-id pub-id-type="doi">10.1002/9780470316696</pub-id></nlm-citation></ref><ref id="ref50"><label>50</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Austin</surname><given-names>PC</given-names> </name><name name-style="western"><surname>White</surname><given-names>IR</given-names> </name><name name-style="western"><surname>Lee</surname><given-names>DS</given-names> </name><name name-style="western"><surname>van Buuren</surname><given-names>S</given-names> </name></person-group><article-title>Missing data in clinical research: a tutorial on multiple imputation</article-title><source>Can J Cardiol</source><year>2021</year><month>09</month><volume>37</volume><issue>9</issue><fpage>1322</fpage><lpage>1331</lpage><pub-id pub-id-type="doi">10.1016/j.cjca.2020.11.010</pub-id><pub-id pub-id-type="medline">33276049</pub-id></nlm-citation></ref><ref id="ref51"><label>51</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Buuren</surname><given-names>S van</given-names> </name><name name-style="western"><surname>Groothuis-Oudshoorn</surname><given-names>K</given-names> </name></person-group><article-title>mice: multivariate imputation by chained equations in R</article-title><source>J Stat Soft</source><year>2011</year><volume>45</volume><issue>3</issue><pub-id pub-id-type="doi">10.18637/jss.v045.i03</pub-id></nlm-citation></ref><ref id="ref52"><label>52</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>White</surname><given-names>IR</given-names> </name><name name-style="western"><surname>Royston</surname><given-names>P</given-names> </name><name name-style="western"><surname>Wood</surname><given-names>AM</given-names> </name></person-group><article-title>Multiple imputation using chained equations: issues and guidance for practice</article-title><source>Stat Med</source><year>2011</year><month>02</month><day>20</day><volume>30</volume><issue>4</issue><fpage>377</fpage><lpage>399</lpage><pub-id pub-id-type="doi">10.1002/sim.4067</pub-id><pub-id pub-id-type="medline">21225900</pub-id></nlm-citation></ref><ref id="ref53"><label>53</label><nlm-citation citation-type="web"><article-title>R: a language and environment for statistical computing (version 4.4.2)</article-title><source>R Core Team</source><year>2024</year><access-date>2025-08-11</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.R-project.org/">https://www.R-project.org/</ext-link></comment></nlm-citation></ref><ref id="ref54"><label>54</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Burnham</surname><given-names>KP</given-names> </name><name name-style="western"><surname>Anderson</surname><given-names>DR</given-names> </name><name name-style="western"><surname>Huyvaert</surname><given-names>KP</given-names> </name></person-group><article-title>AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons</article-title><source>Behav Ecol Sociobiol</source><year>2011</year><month>01</month><volume>65</volume><issue>1</issue><fpage>23</fpage><lpage>35</lpage><pub-id pub-id-type="doi">10.1007/s00265-010-1029-6</pub-id></nlm-citation></ref><ref id="ref55"><label>55</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Holch</surname><given-names>P</given-names> </name><name name-style="western"><surname>Marwood</surname><given-names>JR</given-names> </name></person-group><article-title>EHealth literacy in UK teenagers and young adults: exploration of predictors and factor structure of the eHealth Literacy Scale (eHEALS)</article-title><source>JMIR Form Res</source><year>2020</year><month>09</month><day>8</day><volume>4</volume><issue>9</issue><fpage>e14450</fpage><pub-id pub-id-type="doi">10.2196/14450</pub-id><pub-id pub-id-type="medline">32897230</pub-id></nlm-citation></ref><ref id="ref56"><label>56</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Stellefson</surname><given-names>ML</given-names> </name><name name-style="western"><surname>Shuster</surname><given-names>JJ</given-names> </name><name name-style="western"><surname>Chaney</surname><given-names>BH</given-names> </name><etal/></person-group><article-title>Web-based health information seeking and eHealth literacy among patients living with chronic obstructive pulmonary disease (COPD)</article-title><source>Health Commun</source><year>2018</year><month>12</month><volume>33</volume><issue>12</issue><fpage>1410</fpage><lpage>1424</lpage><pub-id pub-id-type="doi">10.1080/10410236.2017.1353868</pub-id><pub-id pub-id-type="medline">28872905</pub-id></nlm-citation></ref><ref id="ref57"><label>57</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>De Santis</surname><given-names>KK</given-names> </name><name name-style="western"><surname>Jahnel</surname><given-names>T</given-names> </name><name name-style="western"><surname>Sina</surname><given-names>E</given-names> </name><name name-style="western"><surname>Wienert</surname><given-names>J</given-names> </name><name name-style="western"><surname>Zeeb</surname><given-names>H</given-names> </name></person-group><article-title>Digitization and health in Germany: cross-sectional nationwide survey</article-title><source>JMIR Public Health Surveill</source><year>2021</year><month>11</month><day>22</day><volume>7</volume><issue>11</issue><fpage>e32951</fpage><pub-id pub-id-type="doi">10.2196/32951</pub-id><pub-id pub-id-type="medline">34813493</pub-id></nlm-citation></ref><ref id="ref58"><label>58</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Zangger</surname><given-names>G</given-names> </name><name name-style="western"><surname>Mortensen</surname><given-names>SR</given-names> </name><name name-style="western"><surname>Tang</surname><given-names>LH</given-names> </name><name name-style="western"><surname>Thygesen</surname><given-names>LC</given-names> </name><name name-style="western"><surname>Skou</surname><given-names>ST</given-names> </name></person-group><article-title>Association between digital health literacy and physical activity levels among individuals with and without long-term health conditions: data from a cross-sectional survey of 19,231 individuals</article-title><source>Digit Health</source><year>2024</year><volume>10</volume><fpage>20552076241233158</fpage><pub-id pub-id-type="doi">10.1177/20552076241233158</pub-id><pub-id pub-id-type="medline">38410789</pub-id></nlm-citation></ref><ref id="ref59"><label>59</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Wang</surname><given-names>M</given-names> </name><name name-style="western"><surname>Xu</surname><given-names>Y Hua</given-names> </name><name name-style="western"><surname>Ren</surname><given-names>Z qing</given-names> </name><name name-style="western"><surname>Hu</surname><given-names>B li</given-names> </name><name name-style="western"><surname>Zhang</surname><given-names>Y</given-names> </name></person-group><article-title>Associations of electronic health literacy with related factors in individuals diagnosed with colorectal cancer: a cross-sectional analysis</article-title><source>Front Public Health</source><year>2026</year><volume>14</volume><fpage>1681416</fpage><pub-id pub-id-type="doi">10.3389/fpubh.2026.1681416</pub-id></nlm-citation></ref><ref id="ref60"><label>60</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Nymberg</surname><given-names>VM</given-names> </name><name name-style="western"><surname>Bolmsj&#x00F6;</surname><given-names>BB</given-names> </name><name name-style="western"><surname>Wolff</surname><given-names>M</given-names> </name><name name-style="western"><surname>Calling</surname><given-names>S</given-names> </name><name name-style="western"><surname>Gerward</surname><given-names>S</given-names> </name><name name-style="western"><surname>Sandberg</surname><given-names>M</given-names> </name></person-group><article-title>&#x201C;Having to learn this so late in our lives&#x2026;&#x201D; Swedish elderly patients&#x2019; beliefs, experiences, attitudes and expectations of e-health in primary health care</article-title><source>Scand J Prim Health Care</source><year>2019</year><month>03</month><volume>37</volume><issue>1</issue><fpage>41</fpage><lpage>52</lpage><pub-id pub-id-type="doi">10.1080/02813432.2019.1570612</pub-id><pub-id pub-id-type="medline">30732519</pub-id></nlm-citation></ref><ref id="ref61"><label>61</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Britt</surname><given-names>RK</given-names> </name><name name-style="western"><surname>Hatten</surname><given-names>KN</given-names> </name></person-group><article-title>Need for cognition and electronic health literacy and subsequent information seeking behaviors among university undergraduate students</article-title><source>Sage Open</source><year>2013</year><month>01</month><day>1</day><volume>3</volume><issue>4</issue><pub-id pub-id-type="doi">10.1177/2158244013508957</pub-id></nlm-citation></ref><ref id="ref62"><label>62</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Kerr</surname><given-names>G</given-names> </name><name name-style="western"><surname>Greenfield</surname><given-names>G</given-names> </name><name name-style="western"><surname>Bottle</surname><given-names>A</given-names> </name><etal/></person-group><article-title>Patterns of online consultation use in Great Britain, 2019&#x2013;2023: an observational analysis</article-title><source>BMJ Digit Health</source><year>2025</year><month>07</month><volume>1</volume><issue>1</issue><fpage>e000032</fpage><pub-id pub-id-type="doi">10.1136/bmjdhai-2025-000032</pub-id></nlm-citation></ref><ref id="ref63"><label>63</label><nlm-citation citation-type="report"><person-group person-group-type="author"><name name-style="western"><surname>Davies</surname><given-names>AR</given-names> </name><name name-style="western"><surname>Sharp</surname><given-names>CA</given-names> </name><name name-style="western"><surname>Homolova</surname><given-names>L</given-names> </name><etal/></person-group><article-title>Population health in a digital age the use of digital technology to support and monitor health in Wales</article-title><year>2019</year><access-date>2026-06-30</access-date><publisher-name>Public Health Wales; Bangor University</publisher-name><comment><ext-link ext-link-type="uri" xlink:href="https://research.bangor.ac.uk/en/publications/population-health-in-a-digital-age-the-use-of-digital-technology-/">https://research.bangor.ac.uk/en/publications/population-health-in-a-digital-age-the-use-of-digital-technology-/</ext-link></comment></nlm-citation></ref><ref id="ref64"><label>64</label><nlm-citation citation-type="web"><article-title>Technology tracker</article-title><source>Ofcom</source><year>2024</year><access-date>2025-05-13</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.ofcom.org.uk/about-ofcom/our-research/statistical-release-calendar-2024">https://www.ofcom.org.uk/about-ofcom/our-research/statistical-release-calendar-2024</ext-link></comment></nlm-citation></ref><ref id="ref65"><label>65</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Huxley</surname><given-names>CJ</given-names> </name><name name-style="western"><surname>Atherton</surname><given-names>H</given-names> </name><name name-style="western"><surname>Watkins</surname><given-names>JA</given-names> </name><name name-style="western"><surname>Griffiths</surname><given-names>F</given-names> </name></person-group><article-title>Digital communication between clinician and patient and the impact on marginalised groups: a realist review in general practice</article-title><source>Br J Gen Pract</source><year>2015</year><month>12</month><volume>65</volume><issue>641</issue><fpage>e813</fpage><lpage>21</lpage><pub-id pub-id-type="doi">10.3399/bjgp15X687853</pub-id><pub-id pub-id-type="medline">26622034</pub-id></nlm-citation></ref><ref id="ref66"><label>66</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Yoon</surname><given-names>J</given-names> </name><name name-style="western"><surname>Yang</surname><given-names>S</given-names> </name><name name-style="western"><surname>Kang</surname><given-names>SJ</given-names> </name><etal/></person-group><article-title>Digital health literacy in the general population: national cross-sectional survey study</article-title><source>J Med Internet Res</source><year>2025</year><volume>27</volume><fpage>e67780</fpage><pub-id pub-id-type="doi">10.2196/67780</pub-id></nlm-citation></ref><ref id="ref67"><label>67</label><nlm-citation citation-type="web"><article-title>Population of England and Wales&#x2014;ethnicity facts and figures</article-title><source>Office for National Statistics</source><year>2022</year><access-date>2025-08-08</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.ethnicity-facts-figures.service.gov.uk/uk-population-by-ethnicity/national-and-regional-populations/population-of-england-and-wales/latest/">https://www.ethnicity-facts-figures.service.gov.uk/uk-population-by-ethnicity/national-and-regional-populations/population-of-england-and-wales/latest/</ext-link></comment></nlm-citation></ref><ref id="ref68"><label>68</label><nlm-citation citation-type="web"><article-title>Language, England and Wales: Census 2021</article-title><source>Office for National Statistics</source><year>2022</year><access-date>2025-09-08</access-date><comment><ext-link ext-link-type="uri" xlink:href="https://www.ons.gov.uk/peoplepopulationandcommunity/culturalidentity/language/bulletins/languageenglandandwales/census2021">https://www.ons.gov.uk/peoplepopulationandcommunity/culturalidentity/language/bulletins/languageenglandandwales/census2021</ext-link></comment></nlm-citation></ref><ref id="ref69"><label>69</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Milanti</surname><given-names>A</given-names> </name><name name-style="western"><surname>Norman</surname><given-names>C</given-names> </name><name name-style="western"><surname>Chan</surname><given-names>DNS</given-names> </name><name name-style="western"><surname>So</surname><given-names>WKW</given-names> </name><name name-style="western"><surname>Skinner</surname><given-names>H</given-names> </name></person-group><article-title>eHealth literacy 3.0: updating the Norman and Skinner 2006 Model</article-title><source>J Med Internet Res</source><year>2025</year><month>03</month><day>11</day><volume>27</volume><fpage>e70112</fpage><pub-id pub-id-type="doi">10.2196/70112</pub-id><pub-id pub-id-type="medline">40068166</pub-id></nlm-citation></ref><ref id="ref70"><label>70</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>van der Vaart</surname><given-names>R</given-names> </name><name name-style="western"><surname>Drossaert</surname><given-names>C</given-names> </name></person-group><article-title>Development of the digital health literacy instrument: measuring a broad spectrum of health 1.0 and Health 2.0 skills</article-title><source>J Med Internet Res</source><year>2017</year><month>01</month><day>24</day><volume>19</volume><issue>1</issue><fpage>e27</fpage><pub-id pub-id-type="doi">10.2196/jmir.6709</pub-id><pub-id pub-id-type="medline">28119275</pub-id></nlm-citation></ref><ref id="ref71"><label>71</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Levin-Zamir</surname><given-names>D</given-names> </name><name name-style="western"><surname>Van den Broucke</surname><given-names>S</given-names> </name><name name-style="western"><surname>B&#x00ED;r&#x00F3;</surname><given-names>&#x00C9;</given-names> </name><etal/></person-group><article-title>Measuring digital health literacy and its associations with determinants and health outcomes in 13 countries</article-title><source>Front Public Health</source><year>2025</year><volume>13</volume><fpage>1472706</fpage><pub-id pub-id-type="doi">10.3389/fpubh.2025.1472706</pub-id><pub-id pub-id-type="medline">40182520</pub-id></nlm-citation></ref><ref id="ref72"><label>72</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Yoon</surname><given-names>J</given-names> </name><name name-style="western"><surname>Lee</surname><given-names>M</given-names> </name><name name-style="western"><surname>Ahn</surname><given-names>JS</given-names> </name><etal/></person-group><article-title>Development and validation of digital health technology literacy assessment questionnaire</article-title><source>J Med Syst</source><year>2022</year><month>01</month><day>24</day><volume>46</volume><issue>2</issue><fpage>13</fpage><pub-id pub-id-type="doi">10.1007/s10916-022-01800-8</pub-id><pub-id pub-id-type="medline">35072816</pub-id></nlm-citation></ref><ref id="ref73"><label>73</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Sterne</surname><given-names>JAC</given-names> </name><name name-style="western"><surname>White</surname><given-names>IR</given-names> </name><name name-style="western"><surname>Carlin</surname><given-names>JB</given-names> </name><etal/></person-group><article-title>Multiple imputation for missing data in epidemiological and clinical research: potential and pitfalls</article-title><source>BMJ</source><year>2009</year><month>06</month><day>29</day><volume>338</volume><issue>jun29 1</issue><fpage>b2393</fpage><pub-id pub-id-type="doi">10.1136/bmj.b2393</pub-id><pub-id pub-id-type="medline">19564179</pub-id></nlm-citation></ref><ref id="ref74"><label>74</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Grund</surname><given-names>S</given-names> </name><name name-style="western"><surname>L&#x00FC;dtke</surname><given-names>O</given-names> </name><name name-style="western"><surname>Robitzsch</surname><given-names>A</given-names> </name></person-group><article-title>Pooling ANOVA results from multiply imputed datasets</article-title><source>Methodology (Gott)</source><year>2016</year><month>07</month><volume>12</volume><issue>3</issue><fpage>75</fpage><lpage>88</lpage><pub-id pub-id-type="doi">10.1027/1614-2241/a000111</pub-id></nlm-citation></ref><ref id="ref75"><label>75</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Berkowsky</surname><given-names>RW</given-names> </name></person-group><article-title>Exploring predictors of eHealth literacy among older adults: findings from the 2020 CALSPEAKS survey</article-title><source>Gerontol Geriatr Med</source><year>2021</year><volume>7</volume><fpage>23337214211064227</fpage><pub-id pub-id-type="doi">10.1177/23337214211064227</pub-id><pub-id pub-id-type="medline">34926723</pub-id></nlm-citation></ref><ref id="ref76"><label>76</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Arcury</surname><given-names>TA</given-names> </name><name name-style="western"><surname>Sandberg</surname><given-names>JC</given-names> </name><name name-style="western"><surname>Melius</surname><given-names>KP</given-names> </name><etal/></person-group><article-title>Older adult internet use and eHealth literacy</article-title><source>J Appl Gerontol</source><year>2020</year><month>02</month><volume>39</volume><issue>2</issue><fpage>141</fpage><lpage>150</lpage><pub-id pub-id-type="doi">10.1177/0733464818807468</pub-id><pub-id pub-id-type="medline">30353776</pub-id></nlm-citation></ref><ref id="ref77"><label>77</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Adjekum</surname><given-names>A</given-names> </name><name name-style="western"><surname>Blasimme</surname><given-names>A</given-names> </name><name name-style="western"><surname>Vayena</surname><given-names>E</given-names> </name></person-group><article-title>Elements of trust in digital health systems: scoping review</article-title><source>J Med Internet Res</source><year>2018</year><month>12</month><day>13</day><volume>20</volume><issue>12</issue><fpage>e11254</fpage><pub-id pub-id-type="doi">10.2196/11254</pub-id><pub-id pub-id-type="medline">30545807</pub-id></nlm-citation></ref><ref id="ref78"><label>78</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Catapan</surname><given-names>S de C</given-names> </name><name name-style="western"><surname>Sazon</surname><given-names>H</given-names> </name><name name-style="western"><surname>Zheng</surname><given-names>S</given-names> </name><etal/></person-group><article-title>A systematic review of consumers&#x2019; and healthcare professionals&#x2019; trust in digital healthcare</article-title><source>NPJ Digit Med</source><year>2025</year><month>02</month><day>21</day><volume>8</volume><issue>1</issue><fpage>115</fpage><pub-id pub-id-type="doi">10.1038/s41746-025-01510-8</pub-id><pub-id pub-id-type="medline">39984678</pub-id></nlm-citation></ref><ref id="ref79"><label>79</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Dong</surname><given-names>Q</given-names> </name><name name-style="western"><surname>Liu</surname><given-names>T</given-names> </name><name name-style="western"><surname>Liu</surname><given-names>R</given-names> </name><name name-style="western"><surname>Yang</surname><given-names>H</given-names> </name><name name-style="western"><surname>Liu</surname><given-names>C</given-names> </name></person-group><article-title>Effectiveness of digital health literacy interventions in older adults: single-arm meta-analysis</article-title><source>J Med Internet Res</source><year>2023</year><volume>25</volume><fpage>e48166</fpage><pub-id pub-id-type="doi">10.2196/48166</pub-id></nlm-citation></ref><ref id="ref80"><label>80</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Kelly</surname><given-names>JT</given-names> </name><name name-style="western"><surname>Caffery</surname><given-names>LJ</given-names> </name><name name-style="western"><surname>Thomas</surname><given-names>EE</given-names> </name><etal/></person-group><article-title>Determining the digital health literacy and potential solutions to support people with complex chronic conditions to engage with digital models of care</article-title><source>Patient Educ Couns</source><year>2025</year><month>11</month><volume>140</volume><fpage>109278</fpage><pub-id pub-id-type="doi">10.1016/j.pec.2025.109278</pub-id><pub-id pub-id-type="medline">40780114</pub-id></nlm-citation></ref><ref id="ref81"><label>81</label><nlm-citation citation-type="journal"><person-group person-group-type="author"><name name-style="western"><surname>Norman</surname><given-names>C</given-names> </name></person-group><article-title>eHealth literacy 2.0: problems and opportunities with an evolving concept</article-title><source>J Med Internet Res</source><year>2011</year><month>12</month><day>23</day><volume>13</volume><issue>4</issue><fpage>e125</fpage><pub-id pub-id-type="doi">10.2196/jmir.2035</pub-id><pub-id pub-id-type="medline">22193243</pub-id></nlm-citation></ref></ref-list><app-group><supplementary-material id="app1"><label>Multimedia Appendix 1</label><p>Operationalization of PROGRESS-Plus framework in the survey.</p><media xlink:href="jmir_v28i1e89136_app1.doc" xlink:title="DOC File, 433 KB"/></supplementary-material><supplementary-material id="app2"><label>Multimedia Appendix 2</label><p>eHealth Literacy Scale. Each item is answered on a 5-point Likert scale with response options ranging from &#x201C;strongly disagree&#x201D; to &#x201C;strongly agree.&#x201D; Based on Norman and Skinner [<xref ref-type="bibr" rid="ref28">28</xref>].</p><media xlink:href="jmir_v28i1e89136_app2.doc" xlink:title="DOC File, 420 KB"/></supplementary-material><supplementary-material id="app3"><label>Multimedia Appendix 3</label><p>eHealth Literacy Scale distribution (N=1525).</p><media xlink:href="jmir_v28i1e89136_app3.png" xlink:title="PNG File, 55 KB"/></supplementary-material><supplementary-material id="app4"><label>Multimedia Appendix 4</label><p>Odds of low digital health literacy from univariable and multivariable logistic regression models.</p><media xlink:href="jmir_v28i1e89136_app4.docx" xlink:title="DOCX File, 515 KB"/></supplementary-material><supplementary-material id="app5"><label>Multimedia Appendix 5</label><p>Odds of low digital health literacy from univariable and multivariable logistic regression models, among participants with a health condition (N=850).</p><media xlink:href="jmir_v28i1e89136_app5.docx" xlink:title="DOCX File, 209 KB"/></supplementary-material><supplementary-material id="app6"><label>Multimedia Appendix 6</label><p>Odds of low digital health literacy from univariable and multivariable logistic regression models, using the sample median as an alternative eHealth Literacy Scale cutoff.</p><media xlink:href="jmir_v28i1e89136_app6.doc" xlink:title="DOC File, 435 KB"/></supplementary-material><supplementary-material id="app7"><label>Multimedia Appendix 7</label><p>Odds of low digital health literacy from multivariable logistic regression: results of interaction term testing including age by sex, age by education, and sex by education interaction terms.</p><media xlink:href="jmir_v28i1e89136_app7.docx" xlink:title="DOCX File, 512 KB"/></supplementary-material><supplementary-material id="app8"><label>Multimedia Appendix 8</label><p><bold>.</bold>Odds of low digital health literacy from multivariable logistic regression: complete case analysis versus multiple imputation.</p><media xlink:href="jmir_v28i1e89136_app8.docx" xlink:title="DOCX File, 518 KB"/></supplementary-material><supplementary-material id="app9"><label>Checklist 1</label><p>STROBE (Strengthening the Reporting of Observational Studies in Epidemiology)checklist.</p><media xlink:href="jmir_v28i1e89136_app9.pdf" xlink:title="PDF File, 82 KB"/></supplementary-material></app-group></back></article>