Medical masks in COVID-19
Trial question
Is medical mask noninferior to N95 respirator for COVID-19 prevention in healthcare workers?
Study design
Multi-center
Open label
RCT
Population
Characteristics of study participants
70.0% female
30.0% male
N = 1004
1004 patients (699 female, 305 male).
Inclusion criteria: healthcare workers who provided direct care to patients with suspected or confirmed COVID-19.
Key exclusion criteria: nurses with ≥ 1 comorbidities; nurses who cannot pass an N95 respirator fit-test.
Interventions
N=497 medical mask (medical mask worn when providing care to patient with febrile respiratory illness).
N=507 N95 respirator (N95 respirator worn when providing care to patient with febrile respiratory illness).
Primary outcome
Reverse transcriptase-polymerase chain reaction-confirmed COVID-19
10.46%
9.27%
10.5 %
7.8 %
5.2 %
2.6 %
0.0 %
Medical
mask
N95
respirator
Difference not exceeding
non-inferiority
margin ✓
Difference not exceeding non-inferiority margin in reverse transcriptase-PCR-confirmed COVID-19 (10.46% vs. 9.27%; HR 1.14, 95% CI 0.77 to 1.69).
Secondary outcomes
No significant difference in acute respiratory illness (5.4% vs. 6.1%; HR 0.89, 95% CI 0.53 to 1.49).
No significant difference in lower respiratory infection or pneumonia (0.6% vs. 0.6%; HR 1.02, 95% CI 0.21 to 5.04).
No significant difference in laboratory-confirmed infection (14.5% vs. 13.6%; HR 1.08, 95% CI 0.75 to 1.55).
Safety outcomes
No significant difference in adverse events.
Conclusion
In healthcare workers who provided direct care to patients with suspected or confirmed COVID-19, medical mask was noninferior to N95 respirator with respect to reverse transcriptase-PCR-confirmed COVID-19.
Reference
Mark Loeb, Amy Bartholomew, Madiha Hashmi et al. Medical Masks Versus N95 Respirators for Preventing COVID-19 Among Health Care Workers. Ann Intern Med. 2022 Dec;175(12):1629-1638.
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