Skip to main content

5MinuteConsult Journal Club

YES, You Should Still Wear a Mask


Study Summary

This systematic review from the Cochrane looked at 78 RCT’s to determine if physical interventions, like masks and hand washing, lower occurrences of “influenza like infections (ILI)/COVID.” The majority of these trials occurred during non-epidemic periods.

They found wearing medical/surgical masks in the community had no significant impact in reported “influenza‐like illness (ILI)/COVID‐19 like illness” and no impact in “laboratory‐confirmed influenza/SARS‐CoV‐2.”  The level of certainty of this evidence was low to moderate.

Regarding N95/P2 respirators vs medical/surgical masks there was no significant benefit on “clinical respiratory illness” but they “may be effective for ILI. They also note that “evidence is limited by imprecision and heterogeneity for these subjective outcomes.” For objective measures like laboratory‐confirmed influenza infection they found N95/P2 masks made little or no difference. The level of certainty of this evidence was low to moderate.

Handwashing, though, was found to statistically improve rates of acute respiratory infections. When restricted to laboratory confirmed ILI/COVID-19 there was no statistical benefit. But when the authors pooled the data, they found hand hygiene was beneficial with low‐certainty evidence and high heterogeneity (meaning the studies were conducted using different methods).

The authors end with: “The risk of bias for the RCTs and cluster‐RCTs was mostly high or unclear.”


Physical interventions like hand washing and masking shows limited data demonstrating effectiveness, but studies found were of inconsistent quality, involved subjective end points (like patient reported ILL/COVID infection) and used different methodologies. More research is needed, especially those conducted during epidemics.


This study is an excellent starting point; they looked at physical measures during non-epidemic times to determine if these lower the rates of ILI/COVID infections.

They found insufficient data to support masking during non-epidemic periods and that hand washing has a small impact on infection outcomes.

The authors found 2 issues that made their level of certainty low. First is a large subset of the populations studied had inconsistent use of masking. The second is the outcomes were self-reported “Influenza Like Infections/COVID” and in others, laboratory criteria to determine infection. Participant compliance with masking and hand washing was subjectively reported by those surveyed, and most of the studies that occurred were NOT during an epidemic.

This a well-done systematic review that came to an excellent conclusion:

“There is a need for large, well‐designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs. “

This is one of those occasions where it is better to be “safe than sorry.” I will keep washing my hands and I still wear a mask seeing patients and when I go into stores. I wear a mask in airports and leave it on till at “cruising altitude” and then put it back on when we “begin our initial descent”.

Life’s short. It took YEARS to prove seat belts lowered mortality rates and years to prove smoking caused lung cancer (the 60’s were fun that way). This study perfectly concludes for more RCT’s, especially during epidemic conditions.

More from 5MinuteConsult

Coronavirus Disease 2019 (COVID-19)

Contributed by Frank J. Domino, March 1, 2023