Log in to MyACC
Medical Masks vs. N95 Respirators for COVID-19 Among Health Care Workers
Quick Takes
- Among health care workers who took care of patients with suspected or confirmed COVID-19, the overall estimates rule out a doubling in hazard of RT-PCR–confirmed COVID-19 for medical masks when compared with N95 respirators.
- The noninferiority margin of 2 was wide and would not have met a more stringent noninferiority threshold (for example, 30% relative increased risk), and firm conclusions about noninferiority may not be made.
- Decisions about mask types in health care workers should be informed by the uncertainty around the estimates and take into account health care worker preferences about potential tradeoffs, N95 respirator availability, and resource constraints.
Study Questions:
Are medical masks noninferior to N95 respirators to prevent coronavirus disease 2019 (COVID-19) in health care workers providing routine care?
Methods:
The investigators conducted a multicenter, randomized, noninferiority trial (Clinical Trials.gov: NCT04296643) at 29 health care facilities in Canada, Israel, Pakistan, and Egypt from May 4, 2020 to March 29, 2022. A total of 1,009 health care workers who provided direct care to patients with suspected or confirmed COVID-19 were enrolled. Use of medical masks versus fit-tested N95 respirators for 10 weeks, plus universal masking, which was the policy implemented at each site, were compared. The primary outcome was confirmed COVID-19 on reverse transcriptase polymerase chain reaction (RT-PCR) test.
Results:
In the intention-to-treat analysis, RT-PCR-confirmed COVID-19 occurred in 52 of 497 (10.46%) participants in the medical mask group versus 47 of 507 (9.27%) in the N95 respirator group (hazard ratio [HR], 1.14 [95% CI, 0.77-1.69]). An unplanned subgroup analysis by country found that in the medical mask group versus the N95 respirator group, RT-PCR-confirmed COVID-19 occurred in 8 of 131 (6.11%) versus 3 of 135 (2.22%) in Canada (HR, 2.83 [CI, 0.75-10.72]), 6 of 17 (35.29%) versus 4 of 17 (23.53%) in Israel (HR, 1.54 [CI, 0.43-5.49]), 3 of 92 (3.26%) versus 2 of 94 (2.13%) in Pakistan (HR, 1.50 [CI, 0.25-8.98]), and 35 of 257 (13.62%) versus 38 of 261 (14.56%) in Egypt (HR, 0.95 [CI, 0.60-1.50]). There were 47 (10.8%) adverse events related to the intervention reported in the medical mask group and 59 (13.6%) in the N95 respirator group.
Conclusions:
The authors concluded that among health care workers who provided routine care to patients with COVID-19, the overall estimates rule out a doubling in hazard of RT-PCR–confirmed COVID-19 for medical masks when compared with N95 respirators.
Perspective:
This study reports that among health care workers who took care of patients with suspected or confirmed COVID-19, the overall estimates rule out a doubling in hazard of RT-PCR–confirmed COVID-19 for medical masks when compared with N95 respirators. However, the noninferiority margin of 2 was wide and would not have met a more stringent noninferiority threshold (for example, 30% relative increased risk), and firm conclusions about noninferiority may not be made. Of note, the subgroup results varied by country, and the overall estimates may not be applicable to individual countries because of treatment effect heterogeneity. At this time, decisions about mask types in health care workers should be informed by the uncertainty around the estimates and take into account health care worker preferences about potential tradeoffs, N95 respirator availability, and resource constraints.
Clinical Topics: COVID-19 Hub, Prevention
Keywords: COVID-19, COVID-19 Testing, Delivery of Health Care, Health Personnel, Masks, N95 Respirators, Primary Prevention, Respiratory Protective Devices, Reverse Transcriptase Polymerase Chain Reaction
< Back to Listings
