Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality in the United States, accounting for more lives lost per year than those lost to cancer and chronic lung disease combined [1]. In 2016, over 360,000 people died from coronary heart disease, which is the most prevalent form of heart disease. Additionally, 1 in every 19 deaths in the United States, on average, was due to stroke. From 2014 to 2015, the economic burden associated with ASCVD was estimated to result in US $351.2 billion in direct and indirect annual costs [1]. Adults with prior ASCVD events are at high risk for recurrence and require contemporary secondary prevention strategies, including behavioral and medical interventions [2]. ASCVD outcomes are also disparate among groups of persons with different social determinants, including persons with lower income, lower education, and racial minority status [3]. Novel technologies may play a role in addressing the barriers contributing to disparities in ASCVD outcomes.

Health information technologies (HITs) have recently emerged as a viable intervention to mitigate the burden of ASCVD [4,5]. HITs, which encompass patient portals, mobile phone interventions, electronic health records, and telemedicine services, are increasingly being used to improve communication between patients and clinicians and to facilitate chronic disease management [6,7]. Approximately 60% of US adults report searching the internet for health information [8]. Around late March/early April 2020, the implementation of telemedicine services to meet patient demand drastically increased in response to the COVID-19 pandemic, which has reached 92,262,621 cases in 223 countries as of January 16, 2021 [9-11]. Historically, however, there has been a “digital divide” in which underserved populations lack access to computers and the internet, thereby serving as a significant barrier to care management utilizing HIT [12]. In recent years, mobile phones have helped in bridging this divide. In terms of options for online access, approximately 25% of Hispanics and 23% of Non-Hispanic Blacks are “smartphone only” internet users in place of traditional home broadband services compared to only 12% of Whites [13]. Non-Hispanic Blacks and Hispanics are also more likely than Non-Hispanic Whites to seek health information via their smartphones [8].

Previous studies on the sociodemographic characteristics of general US adult population using HIT have found that these adults tend to be Whites, women, young, and have a higher income and education level [14-16]. In terms of HIT use among the CVD population, 73% of US adults with or at risk for CVD owned a smartphone and 48% had a health app [17]. Adults with or at risk for CVD were also more likely to share health information from a smartphone/wearable device with a clinician [17]. Few studies utilizing nationally representative databases have assessed sociodemographic differences in HIT use among adults with self-reported ASCVD. To better understand the differences in HIT use among adults with ASCVD, we analyzed the National Health Interview Survey (NHIS). Specifically, we sought to (1) evaluate general technology and HIT use by prior ASCVD status, (2) describe changes in HIT use over time, and (3) describe social determinants of HIT use among US adults with ASCVD. We hypothesized that among adults with prior ASCVD, (1) general technology and HIT use would be lower, (2) HIT use would increase over time, and (3) social determinants of health that are indicative of more vulnerable status would be associated with lower HIT use.

In this nationally representative sample of US adults with and without ASCVD, adoption of HIT among adults with a history of ASCVD was lower than that of HIT among adults without a history of ASCVD. HIT use prevalence was also lower among adults with sociodemographic characteristics that indicate vulnerability, such as unemployment and lower levels of education. Previous studies have found that older adults tend to be less likely to use the internet or search for health information online than younger adults [8,20]. Similar trends in HIT use in the older adult population were found in this analysis as the age groups of 60-69 years and 70+ years exhibited the lowest prevalence of HIT use among all age groups. There are several potential barriers to HIT use in the older adult population, such as limited health literacy, poor usability and accessibility of HIT, and impediments to effective use of HIT due to complications from chronic diseases such as vision impairment [21-23]. Care management and health promotion in older adults have been shown to be enhanced by HIT; thus, designing strategies that address these barriers could further enhance its effectiveness [24]. Younger family members and caregivers could be engaged to assist in HIT use.

Vulnerable populations such as those who earn lower incomes and are unemployed are more likely to suffer the consequences of the digital divide. People who are employed and have higher incomes are more likely to communicate with health care providers via text, phone apps, or social media [16]. This finding was corroborated in our analysis as the respondents that were >200% above the poverty level (poverty income ratio>2) and employed had a higher prevalence of HIT use compared to respondents that were below the poverty level and unemployed. Affordability of HIT is thus of major importance to increase access to potentially beneficial interventions that are currently barred by financial constraints. Education level has been cited as a determinant of HIT use in previous literature, with individuals with a college education being more likely to engage in eHealth behaviors compared to individuals without a college education [25]. Lower educational attainment has also been associated with lower health literacy, and this has resulted in individuals seeking self-management support either in person or by phone rather than through the internet [26]. Our analysis was consistent with these findings as respondents with lower educational attainment (a high school education or less) had the lowest prevalence of HIT use. HIT strategies should address gaps linked to health literacy as patients with sufficient health literacy are more likely to have access to the internet at home, search the web, access health information via the internet, email via the internet, and communicate with health care providers than patients with marginal to low health literacy [27].

Evaluating HIT use by race/ethnicity has been a major area of interest in terms of bridging the gap of the digital divide. Previous studies have reported that in both outpatient and inpatient environments, Black and Hispanic people are less likely to adopt and use patient portals [28,29]. A nationally representative study examining the demographics of users of health-related information obtained via the internet found that users were more likely to be White or Asian people [16]. Our analysis of the US adult population with ASCVD also found that there was a statistically significant lower prevalence of HIT use among Non-Hispanic Black people (prevalence ratio of 0.8, P=.04) but not Hispanic people (prevalence ratio of 0.9, P=.43) compared to White people (reference with prevalence ratio of 1.0) when adjusted for other sociodemographic characteristics. However, HIT use in this analysis did not include mobile devices. In recent years, mobile phones have emerged as a method to bridge the digital divide as they can provide access to internet services. Blacks are more likely to use a mobile phone to search for health information via the internet, and these devices could be used for targeted interventions [8].

An analysis using data from the 2012 and 2014 Health Information National Trends Survey measured preferences and use of HIT among US adults with and without 3 chronic disease conditions (CVD, diabetes, and hypertension) [7]. After adjusting for sociodemographic characteristics, the analysis found no significant association between these cardiovascular comorbidities and HIT use, suggesting that sociodemographic factors may have a greater influence on the adoption of HIT than the chronic diseases themselves [7]. Our analysis among US adults with a history of ASCVD that adjusted for sociodemographic variables did find significant differences in the prevalence of overall HIT use. The difference in the overall use of HIT further highlights that our fundamental approach to launching these technologies should account for the socioeconomic challenges they may face. This study demonstrates the influence that sociodemographic characteristics have on HIT adoption. It is important for clinical and public health professionals to incorporate the social determinants that impact patients’ health in the design of novel HIT to facilitate effective use. Emerging technologies for patients with ASCVD, such as mobile health interventions, telemedicine, and artificial intelligence have the potential to help manage CVD risk factors, reduce rehospitalizations from cardiac causes, and lower overall health care costs [5,30]. Addressing sociodemographic barriers to HIT use in a population with ASCVD can help ensure that these digital interventions meet the needs of these patients at scale.

This study has the following strengths. The NHIS is a large nationally representative survey, and this analysis pooled 8 years of data to increase the statistical power of the models for more accurate comparisons among the study population. However, health conditions such as coronary heart disease and stroke were self-reported, which could result in an underestimation of HIT use among this population if some individuals misclassified their condition. The smaller sample sizes for adults within our selection criterion in the race/ethnicity group, Non-Hispanic multiple races and other races, and the age group of 18-29 years may result in our estimates being less precise for those groups. CVD risk factors such as diabetes mellitus, hyperlipidemia, smoking, and hypertension could also serve as additional indicators of ASCVD outcomes and be included in future models assessing HIT use among the ASCVD population.

This study has the following weaknesses. HIT use was defined as using a computer in the past 12 months to perform a health-related task, and this did not include other mobile devices. According to the analysis of the 2018 Health Information National Trends Survey by Shan et al [17], 92% of US adults with or at risk of CVD owned a cell phone and 81% owned a smartphone in 2019. Mobile health devices have the potential to consolidate these services for patient-clinician communication, and their absence in the assessment may have resulted in an underestimation of use.

In conclusion, overall HIT use was low (25%) among adults with self-reported ASCVD, which may represent a barrier to delivering care via emerging HIT. Adults with ASCVD who were older, less educated, unemployed, racial minorities, not married, and had lesser income showed a lower prevalence of overall HIT use. To scale HIT interventions such as telemedicine, targeted strategies are needed to address the sociodemographic barriers to HIT adoption.