Mask Use Studies Reveal Inconsistency

The Annal of Internal Medicine published the fifth update alert on March 9, 2021, for a living rapid review on the use of masks for the prevention of respiratory virus infections, including SARS-CoV-2, in health care and community settings.

This Alert found the strength of evidence for any mask use versus nonuse in community settings remains low. Other strength-of-evidence ratings related to mask use in community settings were unchanged because of no new evidence.

The comparison of N95 mask only use versus surgical mask use favored the N95, but the difference was not statistically significant (odds ratio, 0.60 [CI, 0.31 to 1.15]). Based on disclosed study limitations and because of inconsistent results across studies, evidence for N95 versus surgical mask use and other comparisons involving mask use and risk for SARS-CoV-2 infection in health care settings remains insufficient.

Furthermore, as with prior updates, there were no new studies on the effectiveness and safety of mask reuse or extended use.

The U.S. CDC announced on March 8, 2021, if you’ve been fully vaccinated with an experimental COVID-19 vaccine, you should still take steps to protect yourself and others in many situations, like wearing a mask, staying at least 6 feet apart from others, and avoiding crowds and poorly ventilated spaces.