N95 respirators and surgical masks for preventing transmission of respiratory infections to healthcare workers (multiple reviews)
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.
At the time of their review, Iannone et al. found that N95 respirators halved the risk of any respiratory infection compared to surgical masks.
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.
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What are the reviews:
Citation: Iannone P, Castellini G, Coclite D et al. The need of health policy perspective to protect healthcare workers during COVID-19 pandemic. A GRADE rapid review on the N95 respirators effectiveness. Plos One. 2020 Jun 3;15(6):e0234025.
In this rapid review, the authors searched for randomized trials comparing N95 respirators and surgical masks for preventing epidemic influenza in healthcare settings. They did not restrict their searches by language of publication and did the search on 21 March 2020. They included 3 cluster randomized trials and 1 non-inferiority study (total: 8736 healthcare worker participants).
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: 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: 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: 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: 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 Evidence Aid combined summaries: Face masks in the community setting, as a protection against respiratory viruses, Face masks to stop the transmission of respiratory viruses from infected people