Association between COVID-19 Outcomes and Mask Mandates, Adherence, and Attitudes

Adjodah, D.; Dinakar, K.; Chinazzi, M.; Fraiberger, S. P.; Pentland, A.; Bates, S.; Staller, K.; Vespignani, A.; Bhatt, D. L.

Using publicly available data, we quantify the impact of mask adherence and mask mandates on COVID-19 outcomes. We show that mask mandates are associated with a statistically significant decrease in daily new cases (-3.24 per 100K), deaths (-0.19 per 100K), and the proportion of hospital admissions (-2.47%) due to COVID-19 between February 1 and September 27, 2020. These effects are large, corresponding to 13% of the highest recorded number of cases, 20% of deaths, and 7% of admission proportion. We also find that mask mandates are linked to a 23.4 percentage point increase in mask adherence in four diverse states, and that mask adherence is associated with improved COVID-19 outcomes. Lastly, using a large novel survey in 68 countries, we find that community mask adherence and attitudes towards masks are associated with a reduction in COVID-19 cases and deaths. Our results have relevant policy implications, indicating the need to maintain and encourage mask-wearing.