N95 vs. Regular Surgical Masks – Distinction Without a Difference?

Initially, we focused on travel bans, we struggled with a shortage of Coronavirus tests and social distancing became a household word. Now, we’re shifting to the challenge of increasing capacity of our health care system. 

Healthcare providers face the challenge of leading the efforts to contain and manage this pandemic in the context of evolving evidence plagued with uncertainty.  With the need for rapid and decisive action, it behooves us to focus on the evidence we do have to guide our path forward. Yesterday’s actions by the Centers for Disease Control and Prevention (CDC) related to Personal Protective Equipment (PPE) are illustrative.

As of March 19, 2020, the CDC updated its recommendations for health care providers regarding the use of masks in the context of known or suspected COVID-19 stating, “…facemasks are an acceptable alternative when the supply of N95 respirators cannot meet the demand.” While it is disturbing that health care workers are facing the shortages of N95 respirators, there is evidence suggesting that this recommendation is quite reasonable.   

A meta-analysis published in the Canadian Medical Association Journal, May 2016, “…found no significant difference between N95 respirators and surgical masks in associated risk of laboratory-confirmed respiratory infection…” Their final conclusion was, “…that there were insufficient data to determine definitively whether N95 respirators are superior to surgical masks in protecting health care workers against transmissible acute respiratory infections in clinical settings.”¹

Another meta-analysis published in Clinical Infectious Diseases in November 2017, revealed that both masks and respirators were effective in reducing the risk of SARS transmission for healthcare workers with odds ratios of 0.13 and 0.12 respectively. Overall, this study showed that respirators were superior to masks for prevention of bacterial but not viral infections.²

These two studies provide some reassurance that the use of masks in the context of COVID-19 provides effective protection. The shortage of PPE for healthcare workers is one of many challenges we will need to overcome in dealing with this pandemic. Reliance on the rich and evolving body of evidence available should serve as a guidepost for all of our actions.