American College of Physicians issues new guidance on effectiveness of masks

Healthcare personnel should wear N95 respirators when in close contact with suspected or known COVID-19 patients, new guidance from the American College of Physicians (ACP) said.

Meanwhile, healthcare personnel, patients and visitors who are not in close contact with suspected or known COVID-19 patients should use surgical masks in healthcare settings to reduce the risk of transmission, according to ACP Practice Points published in the Annals of Internal Medicine on Friday.

While there's a growing consensus that face masks slow the spread of the COVID-19 virus compared with no mask use in the community, many of the studies did not specify mask type, officials said. 

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The guidance aims to give clarity as to which masks to wear when amid a dearth of direct evidence, officials said. ACP based the Practice Points on indirect evidence from other types of coronaviruses, influenza or influenza-like infection because direct evidence based on COVID-19 is still lacking, officials said.

“It’s important to note that lack of direct evidence does not mean that masks are effective or are not effective,” said Jacqueline Fincher, M.D., president of ACP, in a statement. “We will continue to monitor this and update these Practice Points as new evidence becomes available. In the meantime, we support following proper precautions and procedures to reduce infection transmissions.”

Among the practice points, ACP said: 

  • Asymptomatic or symptomatic people in community settings should follow community and statewide public health guidelines for mask use, which should take into account factors such as local demographics, epidemiological data and exposure context.
  • Community members should not wear N95 respirators given the absence of demonstrated benefit, the possible harm if not properly fitted and the global shortage of N95 respirators.
  • Individuals should pay close attention to handling masks appropriately to avoid self-contamination, and, even when wearing a mask, it remains critical to employ  other infection prevention precautions and control procedures to reduce transmissions.
  • Workers who interact with many people such as flight attendants, restaurant servers, grocery workers, cab drivers and others may benefit from wearing a surgical or cloth mask. However, the use of masks is not necessary when at home unless a household member has COVID-19. ACP also notes that it is important for clinicians and public health authorities to educate individuals and communities on the appropriate use and disposal of masks, which includes how to put on and remove the mask.

ACP officials said regardless of the type of masks used, individuals still should follow other infection prevention procedures such as physical distancing and proper hand hygiene.