Protective efficient comparisons among all kinds of respirators and masks for health-care workers against respiratory viruses

Abstract

Background: There is no definite conclusion about comparison of better effectiveness between N95 respirators and medical masks in preventing health-care workers (HCWs) from respiratory infectious diseases, so that conflicting results and recommendations regarding the protective effects may cause difficulties for selection and compliance of respiratory personal protective equipment use for HCWs, especially facing with pandemics of corona virus disease 2019. Methods: We systematically searched MEDLINE, Embase, PubMed, China National Knowledge Infrastructure, Wanfang, medRxiv, and Google Scholar from initiation to November 10, 2020 for randomized controlled trials, case-control studies, cohort studies, and cross-sectional studies that reported protective effects of masks or respirators for HCWs against respiratory infectious diseases. We gathered data and pooled differences in protective effects according to different types of masks, pathogens, occupations, concurrent measures, and clinical settings. The study protocol is registered with PROSPERO (registration number: 42020173279). Results: We identified 4165 articles, reviewed the full text of 66 articles selected by abstracts. Six randomized clinical trials and 26 observational studies were included finally. By 2 separate conventional meta-analyses of randomized clinical trials of common respiratory viruses and observational studies of pandemic H1N1, pooled effects show no significant difference between N95 respirators and medical masks against common respiratory viruses for laboratory-confirmed respiratory virus infection (risk ratio 0.99, 95% confidence interval [CI] 0.86–1.13, I 2 = 0.0%), clinical respiratory illness (risk ratio 0.89, 95% CI 0.45–1.09, I 2 = 83.7%, P = .002), influenza-like illness (risk ratio 0.75, 95% CI 0.54–1.05, I 2 = 0.0%), and pandemic H1N1 for laboratory-confirmed respiratory virus infection (odds ratio 0.92, 95% CI 0.49–1.70, I 2 = 0.0%, P = .967). But by network meta-analysis, N95 respirators has a significantly stronger protection for HCWs from betacoronaviruses of severe acute respiratory syndrome, middle east respiratory syndrome, and corona virus disease 2019 (odds ratio 0.43, 95% CI 0.20–0.94). Conclusions: Our results provide moderate and very-low quality evidence of no significant difference between N95 respirators and medical masks for common respiratory viruses and pandemic H1N1, respectively. And we found low quality evidence that N95 respirators had a stronger protective effectiveness for HCWs against betacoronaviruses causative diseases compared to medical masks. The evidence of comparison between N95 respirators and medical masks for corona virus disease 2019 is open to question and needs further study.

Oral Lesions Associated with COVID-19 and the Participation of the Buccal Cavity as a Key Player for Establishment of Immunity against SARS-CoV-2

“…Provide information to staff and provide them with the use of personal protective equipment (N95 respirators, safety goggles, clinical gloves, disposable aprons, and hair covers) [ 190 , 191 ].…”

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.…”

“…The approach we used was systematic and evidence-based. Six out of ten systematic reviews analyzed consisted of meta-analyses [ [20] , [21] , [22] , 25 , 26 ] that favoured N95 respirators over medical masks, while the other four [ 18 , 19 , 23 , 24 , 27 ] did not show that N95 respirators have superior protection effect compared with medical masks at a 95% CI [ 18 , 27 ]. Further analysis with Forest plots for meta-analyses directly comparing N95 respirators with medical masks indicated that N95 respirators offered slightly better protection than medical masks for respiratory illnesses.…”

P2/N95 respirators & surgical masks to prevent SARS-CoV-2 infection: Effectiveness & adverse effects

“…A previous meta-analysis examining the effectiveness of respirators compared to surgical masks in preventing infection of HCWs by respiratory viruses (e.g. influenza, adenovirus, echoviruses and coronaviruses) found no significant difference between surgical masks and respirators ( 11 ), with these findings further supported by a recent network meta-analysis ( 12 ). Inconsistencies related to the understanding of the effectiveness of surgical masks and respirators for preventing SARS-CoV-2 infection among HCWs in different clinical contexts (e.g.…”