Face mask

Daily number of symptomatic HCW tested, SARS-CoV-2 positivity rates, and HCW job-descriptions were collected pre and post Universal HCW facemask policy(March 26). Multiple change point regression was used to model positive-test-rate data. SARS-CoV-2 testing and positivity rates were compared for pre-intervention, transition, post-intervention, and follow-up periods.

Results: Between March 12-August 10, 2020, 19.2% of HCW were symptomatic for COVID-19 and underwent SARS-CoV-2 testing. A single change point was identified ∼March 28-30(95% probability). Before the change point, the odds of a tested HCW having a positive result doubled every 4.5-7.5 days. Post-change-point, the odds of a tested HCW having a positive result halved every 10.5-13.5 days.

Conclusions: Universal facemasks was associated with reducing HCW's risk of acquiring COVID-19 ¹⁾.

¹⁾

Wang DD, O'Neill WW, Zervos MJ, McKinnon JE, Allard D, Alangaden GJ, Schultz LR, Poisson LM, Chu BS, Kalkanis SN, Suleyman G. Association between Implementation of a Universal Face Mask Policy for Healthcare Workers in a Health Care System & SARS-CoV-2 positivity testing rate in Healthcare Workers. J Occup Environ Med. 2021 Feb 15. doi: 10.1097/JOM.0000000000002174. Epub ahead of print. PMID: 33596025.