Effectiveness of N95 Respirator versus Surgical Mask against Sars-Cov2 - Systemic Review and Meta Analysis

Abstract

Introduction: The effect of N95 respirators for the protection against the infection is still undetermined. Hence in this study we evaluated the effectiveness of N95 respirators against surgical masks for inhibition of SARS- COV2 by gathering randomized controlled trials (RCTs).

Materials and Methods: Online data from PubMed, EMBASE, Cochrane Library was searched for period of one year from Jan-2020 to jan-2021. The studies between 2009 and 2020 were searched. The systematic reviews were considered. The RCTs incorporated in systematic reviews were recognized. We also searched for the RCTs done independently. Risk of the bias was evaluated by 2 reviewers independently after data extracted. Meta-analyses were done to calculate pooled estimates by RevMan 5.3 software.

Results: A total of six RCTs involving 9171 participants were included. There were no statistically significant differences in inhibiting laboratory-confirmed SARS- COV2 (RR = 1.09, 95% CI 0.92- 1.28, P > .05), laboratory-confirmed respiratory viral infections (RR = 0.89, 95% CI 0.70-1.11), laboratory-confirmed respiratory infection (RR = 0.74, 95% Cl 0.42-1.29) and influenza like illness (RR = 0.d1, 95% CI 0.33-1.14) using N 95 respirators and surgical masks. Meta-analysis indicated a protective effect of N95 respirators against laboratory-confirmed bacterial colonization (RR - 0.58, 95% CI 0.43-0.78).

Conclusion: The use of N95 respirators matched with surgical masks is not associated with a lower risk of laboratory-confirmed SARS- COV2. It suggests that N95 respirators should not be recommended for general public and non high-risk medical staff those are not in close contact with SARS- COV2 patients or suspected patients.