N95 respirator and surgical mask effectiveness against respiratory viral illnesses in the healthcare setting: A systematic review and meta‐analysis

Abstract

Objective To examine the results, level of evidence, and methodologic quality of original studies regarding surgical mask effectiveness in minimizing viral respiratory illness transmission, and, in particular, the performance of the N95 respirator versus surgical mask. Methods Meta‐analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines with use of PubMed, MEDLINE, and the Cochrane Library databases. Results Eight studies (9164 participants) were included after screening 153 articles. Analyses showed statistically significant differences between N95 respirator versus surgical mask use to prevent influenza‐like‐illness (risk ratio [RR] = 0.81, 95% confidence interval [CI] = 0.68–0.94, P < 0.05), non‐influenza respiratory viral infection (RR = 0.62, 95% CI = 0.52–0.74, P < 0.05), respiratory viral infection (RR = 0.73, 95% CI = 0.65–0.82, P < 0.05), severe acute respiratory syndrome coronavirus (SARS‐CoV) 1 and 2 virus infection (RR = 0.17, 95% CI = 0.06–0.49, P < 0.05), and laboratory‐confirmed respiratory viral infection (RR = 0.75, 95% CI = 0.66–0.84, P < 0.05). Analyses did not indicate statistically significant results against laboratory‐confirmed influenza (RR = 0.87, CI = 0.74–1.03, P > 0.05). Conclusions N95 respirator use was associated with fewer viral infectious episodes for healthcare workers compared with surgical masks. The N95 respirator was most effective in reducing the risk of a viral infection in the hospital setting from the SARS‐CoV 1 and 2 viruses compared to the other viruses included in this investigation. Methodologic quality, risk of biases, and small number of original studies indicate the necessity for further research to be performed, especially in front‐line healthcare delivery settings.

Masking strategy to protect healthcare workers from COVID-19: An umbrella meta-analysis

“…Evidence synthesis: Out of ten included meta-analyses, four were based solely on randomized controlled trials (RCTs) [ [18] , [19] , [20] , [21] ], two exclusively consisted of observational studies [ 22 , 23 ], and four were a mix of RCTs and observational studies [ [24] , [25] , [26] , [27] ]. The number of original studies related to the PICO framework in each meta-analysis ranged from 4 to 32 (mean = 14, median = 9).…”

“…Four meta-analyses conducted the same comparison but on preventing respiratory viral infections (RVIs) and clinical respiratory illnesses. Among these, two favoured N95 respirators over medical/surgical masks in HCWs [ 25 , 26 ] with the 95% CI not including the null; meta-estimates from the other two were not as precisely estimated as 95% CIs included the null value [ 18 , 19 ]. Three meta-analyses compared the protective effect of respiratory PPE (including respirators and medical/surgical masks) with no mask.…”

“… # Reference n Original Study Type Relevant Objective Population and Settings Outcome Relevant Intervention and Comparison Relevant Results 1 Bartoszko et al, 2020 [ 18 ] 4 RCTs Review of studies examining the protective effect between N95 respirators and medical masks for preventing HCWs from laboratory-confirmed RVIs and clinical respiratory illnesses HCWs; health-care settings Laboratory-confirmed RVIs and clinical respiratory illnesses N95 respirators vs. Medical masks Compared with N95 respirators, medical masks were not associated with an odds of increased laboratory-confirmed RVIs (adjusted OR = 1.06, 95% CI = 0.90–1.25) and clinical respiratory illnesses (adjusted OR = 1.49, 95% CI = 0.98–2.28) 2 Chen et al, 2022 [ 24 ] 31 Observational studies and RCTs Review of studies examining the protective effect of masks for preventing RVIs HCWs and non-HCWs laboratory-confirmed RVIs rPPE (all types) vs. no masks N95 respirators were effective in preventing RVIs (Case-Control studies: OR = 0.27, 95% CI = 0.14–0.54, Cohort Studies: RR = 0.30, 95% CI = 0.16–0.58); Surgical masks were effective in preventing RVIs (Cohort Studies: RR = 0.05, 95% CI = 0.00–0.97, RCTs: RR = 0.65, 95% CI: 0.48–0.89). 3 Chu et al, 2020 [ 22 ] 10 Observational studies Review of studies examining the protective effect of N95 respirators (or similar) and surgical masks (or similar, e.g., 12-16-layer cotton masks) for preventing RVIs HCWs and non-HCWs; health-care settings and non-health-care settings RVIs Surgical masks or similar (e.g., 12-16-layer cotton masks) vs. no mask; Health-care settings: N95 respirators or similar vs. no mask Surgical masks or similar associated with a significant reduction in RVIs odds compared with no masks (adjusted OR = 0.33, 95% CI = 0.17–0.61); N95 respirators or similar associated with a significant reduction in RVIs odds compared with no mask (adjusted OR = 0.04, 95% CI = 0.004–0.30) 4 Collins et al, 2021 [ 25 ] 8 Observational studies and RCTs Review of studies examining the protective effect between N95 respirators and surgical masks for preventing HCWs from RVIs HCWs; health-care settings RVIs N95 respirators vs. Surgical masks N95 respirators associated with...…”

SARS CoV-2 Infection among Health Care Workers from Different Health Care Facilities in Western Norway: A Prospective, Cross-Sectional Study

“…Again, the small numbers preclude conclusions, but it might be conceivable that nursing home personnel had received less training in the correct use of PPE than HCWs in hospitals/the ER during the first phases of the pandemic. Other potential explanations could be that only surgical face masks were available at nursing homes, which offer less protection against the transmission of SARS-CoV-2 than N95 respirators [23], or that HCWs were infected with SARS-CoV-2 through non-occupational exposure.…”

Vaccine or Garlic–Is It a Choice? Awareness of Medical Personnel on Prevention of Influenza Infections

“…Some studies have compared the effectiveness of wearing surgical masks with N95 masks in preventing influenza infection [ 25 ]. N95 masks are less available, especially in developing countries.…”