Participant-Centered Engagement for Sustained Adherence to Smartwatches: A 12-Month Prospective Decentralized Digital...

Adherence in digital health studies with extended observation periods (≥ 12 months) is limited, and participant retention considerably reduces with time. The US Food and Drug Administration has issued guidelines for improving participant engagement, adherence, and diversity in digital health studies combined with decentralized procedures. A decentralized digital health study on well-being was designed with protocolized procedures to study the feasibility of participant engagement and technology support to facilitate adherence (wearing the smartwatch ≥ 70% of time) sustained over a 12-month period. At the end of the study, participants were asked about their ease of participation and free-response questions about how wearing the smartwatches impacted their physical wellness. An inductive thematic analysis (ITA) was performed to assess themes of those responses and association with adherence. A total of 298 participants were recruited between 2022 and 2023 (n = 129 in Cohort A in October 22, n = 169 in Cohort B in April 23), with 23% non-white participants accrued. Among the 298 participants accrued, 273 (92% of accrued participants) completed the 12-month study with an average overall adherence of 77.4% (SD = 32.64) wear-time across 12 months. Median adherence of participants whose responses exemplified an ITA theme encompassing perceived behavior changes in sleep and physical activity was higher than those who did not have a response exemplifying that theme. Conversely, those expressing perceived discomfort or intrusiveness of the smartwatch had a statistically lower adherence. These results highlight the crucial roles of technology support and robust engagement efforts to enable sustained adherence over extended follow-up periods in decentralized digital health studies.