June 17, 2020

Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US

Category: Article Summary

Topic: Non-Pharmaceutical Interventions

• A comparison of COVID-19 case trends between US counties (n=2,930) found small differences in case trends comparing between counties with and without face mask mandates before the implementation of the mandate and larger and statistically significant differences in counties after they implemented face mask mandates. Compared to counties that did not implement a face mask mandate, daily case rates declined by 0.9% within 5 days post-mandate and reached a 2% decrease by 21 days post-mandate.  

Lyu and Wehby. (June 2020). Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US. Health Affairs. https://doi.org/10.1377/hlthaff.2020.00818