Sociodemographic predictors of successful screening and subsequent randomization in a digital health hypertension intervention.

Introduction: Clinical trials often enroll nonrepresentative participant samples, limiting generalizability of trial findings. The current analysis explores the influences of remote recruitment and screening protocols on participation in a digital health intervention (DHI) to promote the evidence-based Dietary Approaches to Stop Hypertension (DASH) eating pattern.

Methods: Nourish was a 12-month randomized controlled trial comparing the effectiveness of a DHI to an attention control arm among US adults with hypertension. Participants were recruited using digital approaches; eligible individuals completed several screening steps. We examined associations between sociodemographics and mobile technology use and completion of each screening step and compared those characteristics between randomized and nonrandomized participants (those consented but were screened out before randomization).

Results: A total of 678 adults consented to participate in Nourish; 44% of those consented were randomized ( = 301). Those randomized possessed a higher education level ( < 0.0001); were more likely to use health-related apps ( < 0.0001) and wearables ( < 0.0001); and were older ( = 0.01) than nonrandomized individuals. Randomized adults were more likely to use a desktop/laptop/tablet for Internet access (vs mobile phones) ( = 0.01). No significant association was observed existed between sex, race, ethnicity, income, or geographic density of residence and subsequent randomization.

Conclusions: Participants with lower education levels or limited experience in using mobile technologies may require additional support to participate in DHIs. Future research is needed to evaluate remote clinical trial procedures and impacts on generalizability to achieve equitable clinical trial participation.