PROmotion of COvid-19 VA(X)ccination in the Emergency Department-PROCOVAXED: study protocol for a cluster randomized controlled trial

Background: We conducted in-depth interviews to characterize reasons for COVID-19 vaccine hesitancy in emergency department (ED) patients and developed messaging platforms that may address their concerns. In this trial, we seek to determine whether provision of these COVID-19 vaccine messaging platforms in EDs will be associated with greater COVID-19 vaccine acceptance and uptake in unvaccinated ED patients. Methods: This is a cluster-randomized controlled trial (RCT) evaluating our COVID-19 vaccine messaging platforms in seven hospital EDs (mix of academic, community, and safety-net EDs) in four US cities. Within each study site, we randomized 30 1-week periods to the intervention and 30 1-week periods to the control. Adult patients who have not received a COVID-19 vaccine are eligible with these exclusions: (1) major trauma, intoxication, altered mental status, or critical illness; (2) incarceration; (3) psychiatric chief complaint; and (4) suspicion of acute COVID-19 illness. Participants receive an orally administered Intake survey. During intervention weeks, participants then receive three COVID-19 vaccine messaging platforms (4-min video, one-page informational flyer and a brief, scripted face-to-face message delivered by an ED physician or nurse); patients enrolled during non-intervention weeks do not receive these platforms. Approximately, an hour after intake surveys, participants receive a Vaccine Acceptance survey during which the primary outcome of acceptance of the COVID-19 vaccine in the ED is ascertained. The other primary outcome of receipt of a COVID-19 vaccine within 32 days is ascertained by electronic health record review and phone follow-up. To determine whether provision of vaccine messaging platforms is associated with a 7% increase in vaccine acceptance and uptake, we will need to enroll 1290 patients. Discussion: Highlighting the difficulties of trial implementation during the COVID-19 pandemic in acute care settings, our novel trial will lay the groundwork for delivery of public health interventions to vulnerable populations whose only health care access occurs in EDs. Conclusions: Toward addressing vaccine hesitancy in vulnerable populations who seek care in EDs, our cluster-RCT will determine whether implementation of vaccine messaging platforms is associated with greater COVID-19 vaccine acceptance and uptake in unvaccinated ED patients.