As 2021 begins, Health Affairs has taken one last look back at 2020 to tally its 20 most-read articles of 2020, an annual tradition. Read the full list (email registration may be required to read the article).

Atop this year’s list is a study published in June by Wei Lyu and George Wehby, both with University of Iowa Department of Health Management and Policy, estimating the effect of face cover mandates between April 1 and May 21, 2020. According to the authors, face mask mandates resulted in preventing as many as 230,000–450,000 US COVID-19 cases by May 22. Since its publication the study has been repeatedly cited, both in the media and in a range of other sources, in discussions about the benefits of face coverings.

Lyu and Wehby had a second article on shelter-in-place orders that ranked No. 20 for the year.

Links to the articles:

Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US, by Wei Lyu and George L. Wehby

Shelter-In-Place Orders Reduced COVID-19 Mortality And Reduced The Rate Of Growth In Hospitalizations by Wei Lyu and George L. Wehby