Here are some reasons why the conclusions of this Cochrane Review are misleading. And RCTs should be combined in a meta-analysis only if they are all addressing the same research question in the same way. For other questions, a mix of study designs is better. This approach assumes (a) RCTs are the “best” evidence and (b) combining results from multiple RCTs will give you an average “effect size”.īut RCTs are only the undisputed gold standard for certain kinds of questions. A meta-analysis pools the results of multiple studies. RCTs test an intervention in one group and compare it with a “control” group that doesn’t receive the intervention or receives a different intervention. The Cochrane Review combined randomised controlled trials (RCTs) using meta-analysis. However there are problems with the review’s methodology and its underpinning assumptions about transmission. 'Wearing masks in the community probably makes little or no difference to the outcome of laboratory‐confirmed influenza/SARS‐CoV‐2 compared to not wearing masks' Review. The question of whether and to what extent face masks work to prevent respiratory infections such as COVID and influenza has split the scientific community for decades.Īlthough there is strong evidence face masks significantly reduce transmission of such infections both in health-care settings and in the community, some experts do not agree.Īn updated Cochrane Review published last week is the latest to suggest face masks don’t work in the community.

Fluid mask 3 trial