ABSTRACT
BACKGROUND: Quantification of the impact of local masking policies may help guide future policy interventions to reduce SARS-COV-2 disease transmission. This study's objective was to identify factors associated with adherence to masking and social distancing guidelines. METHODS: Faculty from 16 U.S. colleges and universities trained 231 students in systematic direct observation. They assessed correct mask use and distancing in public settings in 126 US cities from September 2020 through August 2021. RESULTS: Of 109,999 individuals observed in 126 US cities, 48% wore masks correctly with highest adherence among females, teens and seniors and lowest among non-Hispanic whites, those in vigorous physical activity, and in larger groups (P < .0001). Having a local mask mandate increased the odds of wearing a mask by nearly 3-fold (OR = 2.99, P = .0003) compared to no recommendation. People observed in non-commercial areas were least likely to wear masks. Correct mask use was greatest in December 2020 and remained high until June 2021 (P < .0001). Masking policy requirements were not associated with distancing. DISCUSSION: The strong association between mask mandates and correct mask use suggests that public policy has a powerful influence on individual behavior. CONCLUSIONS: Mask mandates should be considered in future pandemics to increase adherence.