Smith, J., MacDougall, C., Johnstone, J., et al. (2016). Effectiveness of N95 Respirators Versus Surgical Masks in Protecting Health Care Workers from Acute Respiratory Infection: A Systematic Review and Meta-Analysis. Canadian Medical Association Journal. 188(8):567-574.
The authors conducted a meta-analysis of both clinical studies and surrogate exposure studies comparing N95 respirators to surgical masks to prevent transmission of acute respiratory infections. While the surrogate studies suggested a protective advantage of N95 respirators over surgical masks, the meta-analysis showed insufficient data to definitely determine whether N95 respirators are more protective.