N95 respirators and surgical masks for preventing transmission of respiratory infections to healthcare workers

Added August 3, 2020

What is this? Masks are worn to try to prevent the transmission of respiratory viruses and several systematic reviews have assessed the effects of healthcare workers wearing them. More details, including citations and links to the full reviews used in this summary, are available by scrolling down this summary.

What works: Medical masks and N95 respirators reduce the risk of respiratory infection when worn by healthcare workers.

N95 respirators provide greater protection than medical masks against some types of respiratory infection when worn by healthcare workers, but universal use of N95 respirators throughout a work shift is likely to be less acceptable because of greater discomfort.

MacIntyre et al. reported that respirators were only effective if worn by healthcare workers throughout a work shift.

Verbeek et al. reported that adding tabs to grab masks may decrease the risk of contamination.

What doesn’t work: Disposable, cotton or paper masks are not recommended for protecting healthcare workers from respiratory infection.

MacIntyre et al. reported that targeted use of respirators by healthcare workers for high-risk aerosol-generating procedures was not effective.

What’s uncertain: Mukerji et al. reported there was insufficient economic evidence relating to the use of masks or respirators for reducing transmission of respiratory viruses. When considering the costs of these devices, costs should include those of the device itself and the associated fit testing and training.

What are the reviews:

Citation: MacIntyre CR, Chughtai AA. A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients. International Journal of Nursing Studies. 2020 Apr 30:108:103629.

In this rapid review, the authors searched for randomized trials of the use of respiratory protection by healthcare workers, sick patients and community members. They restricted their searches to articles published in English and did the most recent search on 17 April 2020. They included 19 randomized trials, six of which related to healthcare workers.

Citation: Offeddu V, Yung CF, Low MSF, et al. Effectiveness of masks and respirators against respiratory infections in healthcare workers: a systematic review and meta-analysis. Clinical Infectious Diseases 2017;65(11):1934-42

In this systematic review, the authors searched for studies of the effects of respiratory personal protective equipment among healthcare workers in November 2015. They identified 6 randomized trials (and included data from five of these) and 23 observational studies.

Citation: Long Y, Hu T, Liu L, et al. Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis. Journal of Evidence Based Medicine 2020;13(2):93-101

In this systematic review, the authors searched for studies comparing N95 respirators versus surgical masks among patients and healthcare workers. They did the search in January 2020 and included 6 randomized trials.

Citation: Mukerji S, MacIntyre CR, Newall AT. Review of economic evaluations of mask and respirator use for protection against respiratory infection transmission. BMC Infectious Diseases 2015; 15: 413

In this systematic review, the authors searched for economic evaluations of mask or respirator use in August 2014. They included 7 studies.

Citation: Smith JD, MacDougall CC, Johnstone J, et al. 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 2016;188(8):567–574.

In this systematic review, the authors searched for studies comparing N95 respirators versus surgical masks in healthcare workers and others. They restricted their searches to articles published in English up to 2014. They included 3 randomized trials, 3 observational studies and 23 simulated exposure studies.

Citation: Verbeek JH, Rajamaki B, Ijaz S, et al. Personal protective equipment for preventing highly infectious diseases due to exposure to contaminated body fluids in healthcare staff. Cochrane Database of Systematic Reviews 2020;(4):CD011621

In this Cochrane Review, the authors searched for studies of various types of personal protective equipment, including masks. They did the search in March 2020. They identified 1 randomized trial of fitting tabs to masks to help with their removal (20 participants).

Other related summaries:

Evidence Aid has also prepared combined summaries on the following topics:

  • Face Mask Use in the Community
  • Face Mask Use by Symptomatic Individuals in the Community

 

Disclaimer: This summary has been written by staff and volunteers of Evidence Aid in order to make the content of the original document accessible to decision makers who are searching for the available evidence on the coronavirus (COVID-19) but may not have the time, initially, to read the original report in full. This summary is not intended as a substitute for the medical advice of physicians, other health workers, professional associations, guideline developers, or national governments and international agencies. If readers of this summary think that the evidence that is presented within it is relevant to their decision-making they should refer to the content and details of the original article, and the advice and guidelines offered by other sources of expertise, before making decisions. Evidence Aid cannot be held responsible for any decisions made about the coronavirus (COVID-19) on the basis of this summary alone.

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