Face masks: just what the data say

The science supports that face coverings are saving lives through the coronavirus pandemic, yet the controversy trundles on. How much evidence is sufficient?We examined the efficacy and effectiveness of wearing a face mask and also the models studies accessible in the literature by study design, setting, and look at outcome. The data are summarized in the tabular and narrative formats. As the outcomes were dichotomous, like respiratory infection, these were analyzed as pooled Risk Ratios (RRs), for unadjusted estimates.

face mask

Adjusted odds ratios from multivariable regression reported inside studies were pooled as adjusted Odds Ratios (aORs). These are summarized using random effects meta-analysis using the DerSimonian and Laird random effects model (26), with heterogeneity calculated from your Mantel-Haenszel model. Due to the comprehensive meaning of community-based setting, when possible, studies were sub-grouped determined by study design and identified by appropriate setting to investigate potentially different effects on primary outcomes. If enough studies were present, we performed a sensitivity analysis of the primary outcomes selecting routine conditions for community-based setting excluding conditions at the upper chances of gathering. All summary measures were reported having an accompanying 95% confidence interval. Data analyses were performed using RevMan Software.


Three experimental laboratory studies were included (37, 44, 54), that one study having three arms investigating surgical masks, home-made masks (i.e., cotton mask) or no mask; two studies focussed for the comparisons between surgical masks vs. home-made masks or no mask (Supplementary Appendix 5, Supplementary Table 10). According to our PICO, to the SOF GRADE assessment merely the comparison between surgical mask vs. no mask reporting outcome data was considered (54). This suggested a viral load reduction of 0.25 (0.09–0.67) and only breathing apparatus use (risk difference: 324 fewer × 1,000) (Table 3).There is a need to understand how masks may be used during the day, by both children (at school) (50) and adults (at the office). In a study of the effect of mask use on household transmission of SARS-CoV-2, masks were found to be successful, including for the children, as well as the secondary attack rate for kids was found to get only half those of adults. However, the impact of masks on children wasn’t in comparison with adults (10).