Face Mask Use in the Community for Reducing the Spread of COVID-19: A Systematic Review

Abstract

Background: Evidence is needed on the effectiveness of wearing face masks in the community to prevent SARS-CoV-2 transmission.Methods: Systematic review and meta-analysis to investigate the efficacy and effectiveness of face mask use in a community setting and to predict the effectiveness of wearing a mask. We searched MEDLINE, EMBASE, SCISEARCH, The Cochrane Library, and pre-prints from inception to 22 April 2020 without restriction by language. We rated the certainty of evidence according to Cochrane and GRADE approach.Findings: Our search identified 35 studies, including three randomized controlled trials (RCTs) (4,017 patients), 10 comparative studies (18,984 patients), 13 predictive models, nine laboratory experimental studies. For reducing infection rates, the estimates of cluster-RCTs were in favor of wearing face masks vs. no mask, but not at statistically significant levels (adjusted OR 0.90, 95% CI 0.78–1.05). Similar findings were reported in observational studies. Mathematical models indicated an important decrease in mortality when the population mask coverage is near-universal, regardless of mask efficacy. In the best-case scenario, when the mask efficacy is at 95%, the R0 can fall to 0.99 from an initial value of 16.90. Levels of mask filtration efficiency were heterogeneous, depending on the materials used (surgical mask: 45–97%). One laboratory study suggested a viral load reduction of 0.25 (95% CI 0.09–0.67) in favor of mask vs. no mask.Interpretation: The findings of this systematic review and meta-analysis support the use of face masks in a community setting. Robust randomized trials on face mask effectiveness are needed to inform evidence-based policies.PROSPERO registration: CRD42020184963.

Modeling COVID-19 Mortality Across 44 Countries: Face Covering May Reduce Deaths

“…In a meta-analysis of 44 observational studies across 16 countries with a total sample size of 25,697 patients, mask adoption decreased incidence rate with AOR=0.15 (95% CI=0.09, 0.38) 7 ; however, the focus of this meta-analysis was not on the impact of face masks on mortality. Coclite et al 48 and Leffler and colleagues 49 noted a mortality decrease following mask adoption but did not find statistical significance with their modeling.…”

Reduced Perceived Trustworthiness during Face Mask Wearing

“…Although the implications of such initiatives on individual citizens’ mental well-being and loneliness has been researched [ 12 , 13 ], limited research focused on the influence of alteration in aesthetic appearance—caused by face mask use—on the halo effect, particularly the linkage between aesthetic appearance and perceived trustworthiness. Despite the fact that the practice of face mask wearing helped reduce the diffusion of the SARS-CoV-2 [ 14 , 15 ], wearing a mask obscures many of the visual clues that are frequently used in social interactions to assess the psychological states and intents of others [ 16 , 17 ]. Additionally, the same facial characteristics are used to form trait evaluations, such as perceived trustworthiness [ 18 , 19 ].…”

Effects of 105 biological, socioeconomic, behavioural, and environmental factors on the risk of SARS-CoV-2 infection and a severe course of Covid-19: A prospective longitudinal study

“…Based on the results of laboratory tests, it is usually supposed that the wearing of masks, and even more so respirators, protects individuals against infection with SARS-CoV-2 (and not only against transmitting the infection to other people). On the other hand, the results of a metanalytic study show that empirical evidence for this claim is relatively weak 22 . To the best of our knowledge, there is no published prospective longitudinal study that examined the effects of wearing masks on the risk of Covid-19 or its severity.…”