Randomized Comparison of Online Motivational Themes in Clinical Trial Recruitment

Targeted, digital recruitment strategies such as tailored websites using motivational themes may improve recruitment in clinical trials, but their effectiveness remains unclear. We hypothesized that themes emphasizing community well-being, personal health benefits, or access to perks would increase engagement and prescreening sign-ups compared with a standard contribution to science message in a clinical trial focused on Black adults.

We implemented A/B testing of website themes for recruitment in two randomized trials testing the dietary approaches to stop hypertension diet intervention on blood pressure among Black adults. Website themes were derived from predeveloped motivational categories and included (1) contribution to science (control group), (2) community well-being, (3) personal blood pressure improvement, and (4) access to perks (groceries or cash). A/B randomization directed visitors to a theme randomly between June and December 2024. Using an open-source Web analytics platform, we captured data on 2 primary outcomes: (1) sign-up rate defined as the proportion of unique visitors who completed the trial's prescreening form and (2) engagement defined as (a) mean pageviews per session and (b) mean time spent on site per session. We compared themes using the Welch t tests with statistical significance assessed as 2-tailed P<0.05.

Among 11 484 visitors over 6 months, the themes of community well-being (13.8%), personal blood pressure improvement (14.1%), and access to perks (13.1%) all attracted higher sign-up rates than contribution to science (11.1%; P<0.05 for all comparisons). All alternative themes also led to significantly higher mean pageviews compared with the contribution to science theme (P<0.05 for all comparisons), while mean time on site was similar across all themes (range, 52-55 seconds with P>0.05 for all comparisons). There were no statistical differences noted across the 3 alternative motivational themes for these outcomes.

Tailored websites with digital messages emphasizing community well-being, personal health benefits, and access to perks significantly improved engagement and prescreening sign-up rates, demonstrating that they may enhance recruitment within cardiovascular research.

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT05393232 and NCT05121337.