Table 3.
characteristics of included meta-analyses.
| # | 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 significant decreased RVIs risk compared with surgical masks (RVIs (RR = 0.73, 95% CI = 0.65–0.82), SARS-CoV 1 and 2 virus infection (RR = 0.17, 95% CI = 0.06–0.49), and laboratory-confirmed RVIs (RR = 0.75, 95% CI = 0.66–0.84)) |
| 5 | Jefferson et al., 2020 [19] | 4 | RCTs | Review of studies examining the protective effect between N95 respirators and medical masks for preventing HCWs from RVIs and clinical respiratory illnesses | HCWs; health-care settings | RVIs and clinical respiratory illness | N95 respirators vs. Medical masks | N95 respirators did not associate with significant decreased RVIs and clinical respiratory illnesses risks compared with medical masks (clinical respiratory illness (RR = 0.70, 95% CI = 0.45–1.10), influenza-like illness (RR = 0.81, 95% CI = 0.59–1.11), and laboratory-confirmed influenza (RR = 1.05, 95% CI = 0.79–1.40)) |
| 6 | Li et al., 2021b [26] | 32 | Observational studies and RCTs | Review of studies examining the protective effect between N95 respirators and medical masks for preventing HCWs from RVIs and clinical respiratory illnesses | HCWs; health-care settings | RVIs and clinical respiratory illnesses | N95 respirators vs. Medical masks | N95 respirators did not associate with significant decreased RVIs risk compared with medical masks (laboratory-confirmed RVIs (RR = 0.99, 95% CI = 0.86–1.13), clinical respiratory illnesses (RR = 0.89, 95% CI = 0.45–1.09), influenza-like illness (RR = 0.75, 95% CI = 0.54–1.05), and pandemic H1N1 for laboratory-confirmed RVIs (OR = 0.92, 95% CI = 0.49–1.70)) N95 respirators associated with a significant reduction in beta coronaviruses caused infection odds compared with medical masks (adjusted OR = 0.43, 95% CI = 0.20–0.94) |
| 7 | Li et al., 2021a [23] | 6 | Observational studies (case–control) | Review of studies examining the protective effect of rPPE for preventing SARS-CoV-2 virus infection | HCWs and non-HCWs | SARS-CoV-2 virus infection | rPPE (type not reported) vs. no masks; subgroup: N95 respirators vs. no masks |
rPPE associated with a significant reduction in SARS-CoV-2 virus infection odds compared with no masks (adjusted OR = 0.19, 95% CI = 0.09–0.38), with stronger association in HCWs subgroup (adjusted OR = 0.18, 95% CI = 0.09–0.34); N95 respirators associated with a significant reduction in SARS-CoV-2 virus infection odds compared with no masks (adjusted OR = 0.2, 95% CI = 0.09–0.44) |
| 8 | Kunstler et al., 2022 [27] | 21 | Observational studies and RCTs | Review of studies examining the protective effect between N95 respirators or equivalents and surgical masks for preventing HCWs from SARS-CoV-2 virus infection | HCWs; health-care settings | SARS-CoV-2 virus infection | N95 respirators or equivalents vs. Surgical masks | N95 respirators or equivalents did not associate with a significant reduction in SARS-CoV-2 virus infection odds compared with surgical masks (OR = 0.85, 95%CI = 0.72–1.01) |
| 9 | Tran et al., 2021 [20] | 16 | RCTs | Review of studies examining the efficacy of rPPE in preventing respiratory infections | HCWs and non-HCWs; health-care settings and non-health-care settings | Respiratory infections | Network comparison among different types of rPPE (N95 respirator, surgical mask, cloth mask) | Wearing medical masks associated with significant increased respiratory infection risk compared with fit-tested respirators (RR 1.26 95% CI = 1.01–1.56) |
| 10 | Yin et al., 2021 [21] | 6 | RCTs | Review of studies examining the most suitable type of rPPE and manner of wearing to prevent HCWs from RVIs | HCWs; health-care settings | Laboratory-confirmed RVIs | Network comparison among different types of rPPE (N95 respirator, surgical mask, cloth mask) and manners of wearing (continuous, targeted) | Continuous wearing N95 respirators associated with significant decreased RVIs odds compared with other combinations of rPPE and wearing manners (SUCRA = 85.4) |
Note: n =Number of original studies for the relevant objectives; CI =confidence interval; CrI =credibility interval; HCWs =Healthcare workers; OR = Odds Ratio; rPPE =respiratory Personal Protective Equipment; RCTs =Randomized controlled trials; RR =Relative Risk/Risk Ratio; RVIs =Respiratory Viral Infections; SARS-CoV =severe acute respiratory syndrome coronavirus; SUCRA = the Surface Under the Cumulative Ranking curve Analysis.