Abstract
This observational study was conducted to determine the prevalence and correlates of wearing masks at a large Midwestern US university during the COVID-19 pandemic. A total of 7,237 individuals were observed over 24 hours. Overall mask use prevalence was 90.6% (95% confidence interval: 89.9, 91.2); mask use was significantly associated with being indoors (vs outdoors), female (vs male), and at the athletic center (vs the student union).