Post by Nadica (She/Her) on Jul 11, 2024 23:44:44 GMT
Medical masks versus N95 respirators for preventing COVID-19 among health care workers: A secondary analysis of findings inconsistent with prior understanding reflects the expected inferiority of medical masks. - Posted July 9, 2024
Abstract
Background A previously published study is cited as evidence that medical masks (MM) are noninferior to N95 respirators (N95) in the prevention of COVID infections. As COVID is transmitted via infectious aerosols generated during coughing as well as routine activities such as breathing and speaking, and N95s (in contrast to MM) are designed, validated and specified in national standards to provide protection against such hazards, we re-analysed the published data to resolve this unexpected result. Methods Study data was extracted from the publication, and analyses pre-specified in the original study protocol but omitted from the publication were carried out. Anomalies identified in the process were subject to additional analyses for statistical significance. Results Prespecified analyses reverse the reported outcome, which is the product of multiple alterations to the trial that were not introduced into the registry until after publication. Methodological shortcomings include compromised randomization, with statistically significant correlation between female sex and allocation to the higher-risk arm of the trial. Trial conditions and results at unregistered trial sites in Egypt were inconsistent with – but overwhelmed findings from – sites in the registered countries, which reflected the expected inferiority of medical masks. Substantial additional sources of bias were identified. Unexpected patterns were observed in the data. Conclusions The results of the study do not support the claim that medical masks are noninferior to N95s for the prevention of COVID-19.
Abstract
Background A previously published study is cited as evidence that medical masks (MM) are noninferior to N95 respirators (N95) in the prevention of COVID infections. As COVID is transmitted via infectious aerosols generated during coughing as well as routine activities such as breathing and speaking, and N95s (in contrast to MM) are designed, validated and specified in national standards to provide protection against such hazards, we re-analysed the published data to resolve this unexpected result. Methods Study data was extracted from the publication, and analyses pre-specified in the original study protocol but omitted from the publication were carried out. Anomalies identified in the process were subject to additional analyses for statistical significance. Results Prespecified analyses reverse the reported outcome, which is the product of multiple alterations to the trial that were not introduced into the registry until after publication. Methodological shortcomings include compromised randomization, with statistically significant correlation between female sex and allocation to the higher-risk arm of the trial. Trial conditions and results at unregistered trial sites in Egypt were inconsistent with – but overwhelmed findings from – sites in the registered countries, which reflected the expected inferiority of medical masks. Substantial additional sources of bias were identified. Unexpected patterns were observed in the data. Conclusions The results of the study do not support the claim that medical masks are noninferior to N95s for the prevention of COVID-19.