Abstract Body: Introduction: Trial recruitment is a major determinant of study success and participants’ non-arrival at screening visits represents a significant barrier to timely and representative study completion. However, little is known about the participant and study process characteristics associated with non-arrival at study visits.

Objective: To investigate factors associated with non-arrival at initial in-person screening visits in two ongoing randomized controlled trials.

Methods: The Groceries For Black Residents of Boston to Stop Hypertension trials (GoFresh and GoFreshRx) study whether home-delivered DASH-patterned groceries can reduce blood pressure among Black adults in communities characterized by lower median income. In this analysis, we examined sociodemographic and study-related factors potentially associated with participant non-arrival at their initial study visit (defined as rescheduling or not showing up at all). Associations were determined using logistic regression with adjustment for age, sex, and hypertension treatment status.

Results: Among 1152 participants, the non-arrival rate was 37%. Older participants, those with smaller families, less socially vulnerable participants (participants in the 2^nd and 3^rd quartiles of the Social Vulnerability Index), participants informed via mailed brochures, and participants with a shorter time between initial contact and first scheduled visit were more likely to arrive at their initial visits (Table 1). Participant method of contacting the study (e.g. filling out a survey, calling a study-affiliated number, emailing a study-affiliated email address), visit time (Thursday vs. Friday; AM vs. PM), and season of visit were not associated with visit non-arrival.

Conclusion: In this large trial recruitment drive, we identified several participant and study process characteristics associated with non-arrival at screening visits. These factors represent potential targets for future intervention studies that either accommodate patient factors or intervene upon study process barriers to achieve timely and representative recruitment goals.