Key Points Question Do messages delivered by physicians increase COVID-19 knowledge and improve preventive behaviors among White and Black individuals? Findings In this randomized clinical trial of 18 223 White and Black adults, a message delivered by a physician increased COVID-19 knowledge and shifted information-seeking and self-protective behaviors. Effects did not differ by race, and tailoring messages to specific communities did not exhibit a differential effect on knowledge or individual behavior. Meaning These findings suggest that physician messaging campaigns may be effective in persuading members of society from a broad range of backgrounds to seek information and adopt preventive behaviors to combat COVID-19. This randomized clinical trial evaluates whether messages delivered by physicians improve COVID-19 knowledge and preventive behaviors and assesses the differential effectiveness of messages tailored to the Black community. Importance Social distancing is critical to the control of COVID-19, which has disproportionately affected the Black community. Physician-delivered messages may increase adherence to these behaviors. Objectives To determine whether messages delivered by physicians improve COVID-19 knowledge and preventive behaviors and to assess the differential effectiveness of messages tailored to the Black community. Design, Setting, and Participants This randomized clinical trial of self-identified White and Black adults with less than a college education was conducted from August 7 to September 6, 2020. Of 44 743 volunteers screened, 30 174 were eligible, 5534 did not consent or failed attention checks, and 4163 left the survey before randomization. The final sample had 20 460 individuals (participation rate, 68%). Participants were randomly assigned to receive video messages on COVID-19 or other health topics. Interventions Participants saw video messages delivered either by a Black or a White study physician. In the control groups, participants saw 3 placebo videos with generic health topics. In the treatment group, they saw 3 videos on COVID-19, recorded by several physicians of varied age, gender, and race. Video 1 discussed common symptoms. Video 2 highlighted case numbers; in one group, the unequal burden of the disease by race was discussed. Video 3 described US Centers for Disease Control and Prevention social distancing guidelines. Participants in both the control and intervention groups were also randomly assigned to see 1 of 2 American Medical Association statements, one on structural racism and the other on drug price transparency. Main Outcomes and Measures Knowledge, beliefs, and practices related to COVID-19, demand for information, willingness to pay for masks, and self-reported behavior. Results Overall, 18 223 participants (9168 Black; 9055 White) completed the survey (9980 [55.9%] women, mean [SD] age, 40.2 [17.8] years). Overall, 6303 Black participants (34.6%) and 7842 White participants (43.0%) were assigned to the intervention group, and 1576 Black participants (8.6%) and 1968 White participants (10.8%) were assigned to the control group. Compared with the control group, the intervention group had smaller gaps in COVID-19 knowledge (incidence rate ratio [IRR], 0.89 [95% CI, 0.87-0.91]) and greater demand for COVID-19 information (IRR, 1.05 [95% CI, 1.01-1.11]), willingness to pay for a mask (difference, $0.50 [95% CI, $0.15-$0.85]). Self-reported safety behavior improved, although the difference was not statistically significant (IRR, 0.96 [95% CI, 0.92-1.01]; P = .08). Effects did not differ by race ( F = 0.0112; P > .99) or in different intervention groups ( F = 0.324; P > .99). Conclusions and Relevance In this study, a physician messaging campaign was effective in increasing COVID-19 knowledge, information-seeking, and self-reported protective behaviors among diverse groups. Studies implemented at scale are needed to confirm clinical importance. Trial Registration ClinicalTrials.gov Identifier: NCT04502056
【초록키워드】 COVID-19, randomized clinical trial, randomization, social distancing, knowledge, Gender, Masks, prevention, Symptoms, Registration, Adults, Health, Effectiveness, Control, incidence rate, Community, age, Placebo, women, information, Critical, Protective, black, control group, intervention group, individual, COVID-19 knowledge, measure, control groups, white, treatment group, center, participant, Final, finding, physician, Volunteer, Effect, objective, effective, setting, Randomly, IMPROVE, Result, greater, not differ, described, affected, evaluate, the disease, conducted, screened, less, determine, assigned, groups, statistically significant, Importance, recorded, receive, eligible, Point, Relevance, 【제목키워드】 COVID-19, clinical, Practice, black, white, message, Effect, Public,