Objectives Information on the prevalence of face mask use to reduce the spread of SARS-CoV-2 is needed to model disease spread and to assess the effectiveness of policies that encourage face mask use. We sought to (1) estimate the prevalence of face mask use in northern Vermont and (2) assess the effect of age and sex on the likelihood of face mask use. Methods We monitored the entrances to public businesses and visually assessed age, sex, and face mask use. We collected 1004 observations during May 16-30, 2020. We calculated estimates of overall face mask use and odds ratios (ORs) for effects by age and sex. Results Of 1004 observations, 758 (75.5%) sampled people used a face mask. Our census-weighted estimate was 74.1%. A higher percentage of females than males wore face masks (83.8% vs 67.6%). The odds of face mask use were lower among males than among females (OR = 0.52; 95% CI, 0.37-0.73). Face mask use generally decreased with decreasing age: 91.4% among adults aged >60, 70.7% among adults aged 26-60, 74.8% among people aged 15-25, and 53.3% among people aged ≤14. The OR of an adult aged >60 wearing a face mask was 14.70 times higher, for young people aged 15-25 was 2.72 times higher, and for adults aged 26-60 was 2.99 times higher than for people aged ≤14. Females aged >60 had the highest percentage of face mask use (96.3%) and males aged ≤14 had the lowest (43.8%). Conclusions Educational efforts promoting the use of face masks should be targeted at males and younger age groups to limit the spread of SARS-CoV-2.

Mask wearing is integral to reducing the spread of SARS-CoV-2. Information on prevalence of face mask usage is required both to model disease spread and to improve compliance with mask usage through targeted messaging. We sought to (1) estimate the prevalence of mask usage in the most populous county of Vermont (Chittenden County;>25% of state population) and to (2) assess the effect of age and sex on mask use. We monitored the entrances to eight different business types and visually assessed individuals′ age, gender, and mask use from a distance. We collected 1004 observations from 16 May through 30 May 2020 as businesses began to reopen following an extended state-wide lock down. We analyzed these data using a Bayesian random effects logistic regression model. We found that overall 75.5% of individuals used a mask with significant effects of age and gender on mask usage. Females were more likely to wear masks than males (83.8%, n=488 vs. 67.6%, n=516 mask usage, respectively); the odds of a male wearing a mask was 53% that of the female odds. Across age groups, the elderly were most likely to wear a mask (91.4%, n=209) followed by young adults (74.8%, n=246), middle-aged adults (70.7%, n=519) and children (53.3%, n=30). The odds of an elderly person wearing a mask were 16.7 times that of a child, while the odds for young adults and middle-aged adults were ≈3 times greater than a child. Highest mask usage was in elder females (96.3%, n=109) and lowest mask usage was in male children (43.8%, n=16).