Imprecise assessment of mask use may obscure associations with SARS-CoV-2 positivity

Masks are effective measures to prevent the transmission of SARS-CoV-2, however, lack of a national mandate coupled with poor adherence has led to suboptimal levels of transmission reduction. Although data has suggested that mask adherence is high, few studies have captured details on how mask wearing changes with activities and how these behaviors are associated with SARS-CoV-2 positivity. We recruited an online sample of 3,058 respondents from three US states (MD, FL, IL; n[~]1000/state) between September 16 - October 15, 2020. The median age of the sample was 47; 53% were female, 56% were white and 22% were working outside the home. Seventy three percent of the sample reported always wearing a mask indoors and outdoors based on local guidelines, however, 78% of participants who reported always wearing a mask reported taking their mask off when outside the home. While overall masking according to guidelines was not significantly associated with SARS-CoV-2 positivity, sometimes, often or always removing a mask during activities were significantly associated with SARS-CoV-2 positivity (adjusted odds ratio for always vs never removing mask: 9.92; 95% CI: 1.16 - 85.1). These findings suggest that masks were most effective when worn without removal reflecting the need for consistent use.