Does wearing a surgical mask influence face touching by healthcare workers? A retrospective cohort study

Objective At the start of the COVID-19 pandemic, healthcare workers (HCW) in our ED were advised against and actively discouraged from wearing masks when not seeing respiratory patients, as mask wearing was thought to increase the risk of droplet transmission by face touching. The primary objective of the present study was to determine whether HCW using face masks were more or less likely to touch their faces than those not wearing masks. Methods We analysed six randomly selected hours of closed circuit television footage from our staff base. Face touches were recorded electronically by trained researchers. Generalised linear mixed models were used to compare the frequency and duration of face touches with and without face masks, controlling for individual clusters, adjusting for time of footage, duration on screen and staff role. Results Data were collected from 187 HCW. Masks were worn in 231 (36%) of 642 screen sessions. Wearing a mask did not significantly change the odds of face touching (odds ratio 0.55, 95% confidence interval [CI] 0.30-1.01, P = 0.055) or duration of face touch (mean difference -1.45 s, 95% CI -8.84, 5.99, P = 0.71). For mucosal areas, a significant reduction in the odds of face touching was observed for mask wearers (odds ratio 0.21, 95% CI 0.11-0.43, P < 0.001) and on the frequency of mucosal touches (rate ratio 0.45, 95% CI 0.29-0.69, P < 0.001). Conclusions Mask wearing did not change face touching or the duration of face touches. However, significantly fewer mucosal touches were observed when wearing a mask, which may help to reduce nosocomial droplet transmission of viruses.