Antiviral Face Masks for the Prevention of Influenza Infection: a Meta-analysis

Objective: We performed a meta-analysis to examine the effectiveness of face masks for preventing influenza infection. Methods: A literature search was conducted to identify clinical trials that compared the incidence of influenza infection among family members with and without the use of antiviral face masks; some trials also contained the use of hand hygiene in the intervention group. Data from each trial were combined using a random effects model with the DerSimonian-Laird method to calculate pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Results: The meta-analysis included seven randomized controlled trials that met our inclusion criteria. With the use of antiviral face masks, the pooled ORs (95% CIs) of laboratory proven infection were 0.69 (0.22-2.18). The pooled ORs (95% CIs) of influenza-like illness (ILI) were 1.07 (0.65-1.78). With the use of antiviral face masks and concomitant hand hygiene, the pooled ORs (95% CIs) of laboratory proven infection were 0.70 (0.35-1.39) in early intervention cases, and 0.93 (0.66-1.30) in all cases. The pooled ORs (95% CIs) of ILI were 1.01 (0.47-2.19) in early intervention cases, and 1.06 (0.53-2.13) in all cases. Conclusion: No statistically significant differences were detected in the incidence of influenza infection by wearing antiviral face masks, suggesting that distribution of face masks in primary care settings may not be enough to prevent influenza-like illnesses amongst family members.