Abstract P889: Virtual Outcomes: A Possible Strategy to Improve Retention in a Primary Stroke Prevention Trial

Background: Hypertension is the most important modifiable risk factor for stroke and an important contributor to the racial disparities of stroke incidence. Thus, working within the communities in which racial disparities of stroke are prevalent is important.Trials working with such communities may have low participant retention at least partially attributable to social determinants of health such as limited time, transportation and access to medical care. Trial outcome adaptations as a result of the COVID-19 pandemic allowed us to compare in-person to virtual retention strategies as a possible strategy to improve trial retention. Methods: Reach Out is a health system focused, multi-component, health theory based, mobile health behavioral intervention to reduce blood pressure (BP) among Emergency Department (ED) patients at a safety net hospital in the under-resourced, minority, majority community of Flint, Michigan. The primary outcome is change in systolic blood pressure. Outcomes were conducted in-person from 10/4/2019 to 3/13/2020 at various locations throughout the community that were convenient for each participant. As a result of COVID-19 and the resulting state mandated stay-at-home order, outcomes were converted to phone, text, and picture-based elements. Virtual outcomes consists of: 1) a texted picture validating BP cuff is in correct body placement; 2) 3 self-reported blood pressures; and 3) telephone outcome survey. Virtual outcomes were offered at times convenient to participants throughout the daytime, evening, and weekend. Results: Prior to COVID-19, 6-month outcomes were conducted in-person. Of possible in-person outcomes, 76 of 140 (54%) were completed. Tele-outcomes commenced on 4/9/2020. As of 8/18/2020, 63 of 132 (48%) 6-month tele-outcomes, and 38 of 59 (64%) 12-month tele-outcomes have been completed. Total tele-outcomes completed are 101 of 191 (53%). 6 participants have completed 12-month tele-outcomes, who did not complete 6-month in-person outcomes. Conclusion: In a mobile health behavioral intervention to reduce hypertension among patients who received care at a safety-net ED, we found that participant retention was similar between in-person and virtual outcome assessments. Virtual outcomes obviate the need for transportation and childcare, barriers to participation for some participants and could help increase the retention rate in future trials.