Strategies and lessons learned from a longitudinal study to maximize recruitment in the midst of a global pandemic.

The COVID-19 pandemic disrupted many usual processes for recruiting and enrolling research participants. We present our experience with electronic recruitment in a survey study investigating the impact of the COVID-19 pandemic on mental health. Adults (≥18 years) in communities served by Baylor Scott and White Health (BSWH) were recruited via patient portal messages sent to BSWH patients with confirmed/suspected COVID-19 as part of the "COVID-19 Digital Care Journey"; BSWH social media posts; other media; referral from other BSWH COVID-19 studies; and internal BSWH communications. Of 1279 enrolled participants, 996 (77.87%) were recruited via the Digital Care Journey and 124 (9.7%) via internal communications. The remaining strategies contributed <5% each. Social media and internal communications recruited larger proportions of those aged 18 to 34 and those with advanced degrees; other media, more racially diverse participants; and the Digital Care Journey and referral from other studies, predominantly participants positive for COVID-19. In terms of volume, the COVID-19 Digital Care Journey was the most successful strategy, particularly for individuals who had COVID-19. However, its dominance contributed to the overrepresentation of white, educated, and female participants. Thus, supplemental strategies to reach individuals not enrolled/engaging with the portal are necessary to achieve representativeness.