Abstract Body (Do not enter title and authors here): Background: Digital health offers a potential solution to support adults with congenital heart disease (CHD), filling the critical gap to help maintain recommended lifelong care with adult CHD specialists. However, its design and implementation require a rigorous scientific approach to make it scalable and usable for the target population.

Objective: To pilot test the acceptability and feasibility of a digital health intervention to support lifelong healthcare for adults with CHD.

Methods: Using a community-based participatory research and a behavioral theory-based approach, we developed and piloted a digital tool, Empower My Congenital Heart (EmpowerMyCH), within the web—and mobile-based Eureka Digital Research platform at UCSF. Intervention components within EmpowerMyCH include exhibits (expert and peer-developed learning modules on CHD-related topics such as finding specialists or navigating visits, tests, procedures, etc.), peer support, and a digital medical passport (Figure 1). Participants receive an exhibit with study measure surveys every two months, with a two-month completion window. Participant satisfaction with the digital tool is measured at six months using the Client Satisfaction Questionnaire-8 (CSQ-8), a validated survey with scores ranging from 8 to 32; higher scores indicate higher satisfaction with the digital tool.

Results: Of the 519 participants recruited, 495 were eligible adults with CHD, 445 consented, and 6 withdrew. The median age was 43 (ranging from 20 to 85) years, and 30.1% were males. Survey completion rate was the highest at 88.7% during the first two months after enrollment and 53.5% at 8 months. Of the five exhibits delivered so far, over 87% of participants rated the exhibits to be helpful (Figure 2). Participants found the exhibits readable, easily accessible, motivational, useful, and educational (Figure 3). The median (25th, 75th) CSQ-8 score was 21 (18, 25) among 144 participants who completed the survey.

Conclusions: EmpowerMyCH, the digital health tool, appears to be acceptable to most adults with CHD to support and educate them in navigating their healthcare. The tool and its contents are accessible, user-friendly, and responsive to the needs of the CHD community, resulting in high satisfaction rates. The feasibility rates and satisfaction scores are similar to or higher for EmpowerMyCH than those of prior digital health studies. Future hybrid intervention trials can demonstrate EmpowerMyCH‘s effectiveness.