Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers
DMSc Henning Bundgaard, Johan Skov Bundgaard, Daniel Emil Tadeusz Raaschou-Pedersen, DMSc Christian Von Buchwald, MD Tobias Todsen, MD; Jakob Boesgaard Norsk, MD Mia M Pries-Heje, Christoffer Rasmus Vissing, MD Pernille B Nielsen, MD Ulrik C Winsløw, MD; Kamille Fogh, MD Rasmus Hasselbalch, MD Jonas H Kristensen, PhD Anna Ringgaard, Mikkel Porsborg Andersen, PhD Nicole Bakkegård Goecke, PhD Ramona Trebbien, PhD Kerstin Skovgaard, DMSc Thomas Benfield, PhD Henrik Ullum, DMSc Christian Torp-Pedersen, DMSc Kasper Iversen
Annals of Internal Medicine, doi:10.7326/m20-6817
Background: Observational evidence suggests that mask wearing mitigates transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is uncertain if this observed association arises through protection of uninfected wearers (protective effect), via reduced transmission from infected mask wearers (source control), or both. Objective: To assess whether recommending surgical mask use outside the home reduces wearers' risk for SARS-CoV-2 infection in a setting where masks were uncommon and not among recommended public health measures.
Inclusion and exclusion criteria are described in the Methods section, and criteria for completion of the study are given in the Supplement (available at Annals.org). SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2.
ORIGINAL RESEARCH Effectiveness of Mask Recommendation for Preventing SARS-CoV-2 Infection
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