Chronic pain is a major public health problem affecting millions of people worldwide and imposing significant burdens on individuals’ well-being and quality of life. Among chronic pain conditions, fibromyalgia syndrome (FMS) is one of the most prevalent and challenging to treat. FMS involves widespread musculoskeletal pain, fatigue, and debilitating symptoms that impair physical and psychological functioning [1-3]. While pharmacological treatments provide partial relief for some individuals, nonpharmacologic approaches are often needed to improve well-being [4]. Consequently, innovative interventions are required that address the multifaceted impacts of FMS on daily life.

In recent years, positive psychological interventions have emerged as a promising approach to promote well-being and enhance mental health outcomes [5-7]. Integrating daily positive activities into chronic pain treatment has shown the potential to foster resilience and improve overall well-being [8,9]. Daily positive events (PE)—small, meaningful experiences that increase positive emotions [10,11], such as enjoying a pleasant meal, having a meaningful conversation, or experiencing moments of comfort—may be especially beneficial for individuals with FMS. First, cultivating positive emotions, like joy, gratitude, and contentment, through daily PE could improve emotional well-being, as these tend to be deficient in this population [12,13]. Second, actively seeking and savoring positive experiences may instill a greater sense of control and agency over one’s life, counterbalancing feelings of helplessness and hopelessness common in chronic pain [14,15]. Third, pleasant daily activities could facilitate social connection and support, which are essential given individuals with FMS often experience isolation due to their condition [16,17]. Finally, engagement in pleasant activities and PE may facilitate healthy habits and routines, promoting sustained well-being and improvements in daily functioning [18,19].

Internet-delivered positive psychological interventions represent a promising approach to enhancing well-being among those affected by chronic pain, including those with FMS. Web-based programs can overcome barriers to in-person treatment while providing effective tools to boost positive experiences. One such intervention has been widely tested in multiple studies with more than 1000 participants (aged 16 to 78 years) coping with varied life stressors, from diagnosis with a serious illness to daily stress [20-23]. The program has been implemented in person (individually and in groups) and, most recently, has been delivered digitally as a self-guided program for individuals with diabetes [24], depression [25-27], HIV [28], and cancer [21,29] and for the general public during the COVID-19 pandemic [30]. However, research is lacking on how to optimally design such interventions specifically for aging adults with FMS [31].

To address this gap, this study tested a web-based program that integrates prior theoretical work on positive emotions [32-34], stress and coping [35,36], and PE [37,38]. Specifically, we examined the effects of an internet-delivered positive affect (PA) skills intervention, called Lessons in Affect Regulation to Keep Stress and Pain Under Control (LARKSPUR), on daily PE, affect, pain, and fatigue in adults with FMS. LARKSPUR is a self-guided web-based intervention that consists of 8 skills taught over the course of 5 weeks with opportunities for practice of the skills built into the platform. Our initial pilot study demonstrated LARKSPUR’s feasibility and preliminary efficacy at improving overall affect and reducing pain catastrophizing [39]. However, it did not examine fluctuations in participants’ daily experiences, which are hypothesized to be a key mechanism based on LARKSPUR’s theoretical underpinnings [34,39].

We sought to determine if the LARKSPUR intervention could improve daily emotional and functional well-being in adults with FMS by targeting daily PE. Consistent with the Positive Pathways to Health model [34], we hypothesized that participants randomly assigned to LARKSPUR would show greater enhancements in daily PE-related affective well-being, pain, and fatigue compared to participants in the emotion reporting/attention control condition. By using digital technology, this study provides a scalable and accessible intervention that may help overcome barriers to in-person care for individuals with FMS [40,41].

Participants were recruited from July 2021 to June 2022 through referrals from New York State practicing physicians and posted flyers throughout the New York Presbyterian Health Care System, New York City–based senior centers, community centers, and web-based platforms (eg, Facebook groups). Recruitment links were also posted on clinicaltrials.gov and emailed to potential participants via ResearchMatch, a national health volunteer research registry created by several US-based academic institutions and supported by the US National Institutes of Health.

The primary outcomes included affective, pain, and fatigue responsivity to daily PE. PE were assessed with five items asking participants to report whether the following PE had occurred in the past 24 hours: (1) positive interpersonal interaction; (2) positive experience at work, school, or a volunteer position; (3) positive experience at home; (4) network PE (ie, PE experienced by a close friend or relative); and (5) any other PE [10].

PA and NA were assessed using the 20-item modified Differential Emotions Scale, which asked respondents to rate how often they felt 10 positive (eg, amusement, gratitude, and joy) and 10 negative (eg, anger, guilt, and sadness) emotions during the past 24 hours [60]. Items were rated on a 5-point Likert-type scale ranging from 0 (never) to 4 (most of the time).

Pain intensity and fatigue were each measured using a single item with a rating scale from 0 (no pain or fatigue) to 10 (as much pain or fatigue as could be) [61].

Ethics approval was obtained from the Institutional Review Board at Weill Cornell Medicine (protocol number 20-06022291). All participants were informed about the study details and procedures before providing their written consent. The collected data were coded and deidentified. Participation was strictly voluntary, and participants were informed about their right to withdraw from the study at any point without any consequences.

The sample included 95 adults aged 50-80 years. The majority were female (89/95, 94%) and identified as White (76/95, 80%). Of the 142 individuals initially screened for participation, 47 individuals were excluded from the study. The primary reasons for exclusion were not meeting the inclusion criteria (n=22) and declining to participate (n=21). Additional reasons included not providing consent for access to medical records (n=1), inability to access the intervention platform (n=1), and other unspecified reasons (n=2). The remaining 95 eligible participants were enrolled in the study and randomly assigned to either the LARKSPUR intervention or the control condition. All 95 participants completed the baseline questionnaires and were randomly assigned to the LARKSPUR intervention (n=49) or the control (n=46). Using an intention-to-treat analysis, 86 participants (n=43 LARKSPUR and n=43 control) completing baseline and postintervention assessments were included. In addition, participants completing ≥2 daily assessments per measurement burst were included to assess daily changes, resulting in a final analytic sample of 80 participants (n=40 in LARKSPUR and n=40 in control; see the CONSORT [Consolidated Standards of Reporting Trials] diagram in Figure 1). Demographic variables and baseline measures for the analytic sample are summarized in Table 1. As demographic and baseline measures were collected prerandomization, group differences at baseline were not tested [77].

This randomized controlled trial provides initial evidence that LARKSPUR, an internet-delivered PA skills intervention, can enhance responsivity to daily PE in adults with FMS. LARKSPUR led to greater decreases in NA and increases in PA following PE compared to the control condition. It also led to reductions in pain and fatigue following PE at the postintervention and 1-month follow-up time points. These findings suggest that LARKSPUR has the potential to be an accessible and effective eHealth intervention to boost well-being and improve symptom management in this population.

The findings have several strengths and implications for research and practice. First, the results support previous research showing the benefits of positive psychological interventions for populations with chronic pain [13,78]. By targeting engagement in pleasant activities and PE, LARKSPUR aligns with prior work highlighting the value of positive experiences in promoting resilience and well-being [40,41]. Second, the study demonstrates the feasibility and potential of delivering such programs remotely to aging adults with FMS. The web-based format helps overcome barriers to in-person treatment while improving reach, flexibility, and scalability [79-81]. This is especially relevant given COVID-19 contexts demanding flexible health services [82]. Third, incorporating technology into the intervention likely enhanced program quality and engagement through personalized feedback and reminders. These digital components may have facilitated the gains in PE responsivity observed in the LARKSPUR group compared to controls. Fourth, the adaptable nature of LARKSPUR allows for implementation across varied formats to meet diverse user needs and preferences. This tailoring can boost engagement, which is key for patients with chronic pain who have heterogeneous motivations and capacities [8,13]. Finally, the findings provide insights into mechanisms of change. The affective benefits at the postintervention time point suggest LARKSPUR honed positive emotion regulation skills; however, continued practice may be needed to maintain gains. In contrast, the persistence of LARKSPUR’s effects on pain and fatigue through 1-month follow-up indicates the intervention likely produced broader impacts beyond the temporary enhancement of positive emotions.

Several limitations of this study should be acknowledged. The modest sample size limits the precision and generalizability of our findings, highlighting the need for larger, more diverse samples of individuals with fibromyalgia. Future studies should aim to recruit participants from a broader range of demographic groups to examine the effects of LARKSPUR across different populations. Additionally, our reliance on self-report measures may introduce bias, and incorporating objective assessments, such as clinician observations or actigraphy, could provide more robust evidence. Furthermore, our focus on PE frequency was narrow, and exploring the variety of daily experiences may reveal new avenues for improving overall well-being [83-85]. Finally, longer-term follow-up is needed to determine the sustainability of benefits and to investigate strategies for maintaining gains, such as periodic booster sessions.

This randomized trial provides preliminary evidence that a web-based PA skills intervention can enhance responsivity to daily PE across emotional and functional domains in adults with FMS. Specifically, the findings indicate LARKSPUR improved participants’ affective, pain, and fatigue responses following daily positive experiences compared to controls. This provides initial support for the efficacy of technology-based platforms, like LARKSPUR, to boost well-being in this population by targeting sensitivity to daily PE. Further research is needed to replicate these results in a larger sample and address optimizing technology to enhance LARKSPUR’s scalability and efficacy for diverse aging adults with fibromyalgia.