Face mask use to prevent COVID-19 in clinical practice. Using a review of reviews to improve decision-making and...

The COVID-19 pandemic has highlighted the importance of transparency and scientific rigour in the development of clinical guidance. Rapid review methodologies were widely used in the development of guidance, and in the United Kingdom, COVID-19 guidance was criticized for methodological inadequacy and erroneous conclusions.

To summarize the evidence looking at the use of face masks to prevent COVID-19 infection in clinical practice areas, and to show how this can be used in decision-making.

Overview of systematic reviews.

Systematic reviews which included meta-analyses were sought, and data on the protective effect of face masks on COVID-19 transmission were extracted. A total of 15 papers yielded 44 effect sizes suitable for quantitative presentation, which showed wide variation in effect depending on the outcome and intervention chosen.

Guideline development groups need to take care to choose outcomes that are of most importance to those who are the target of guidance. Quantification of the protective effect of interventions such as different types of face mask will help nurses and others decide on the utility of their use, alongside consideration of the other factors that go into informing clinical recommendations.

COVID-19 has been an unprecedented public health issue, but much clinical guidance was lacking in transparency. Nurses and other healthcare professionals have often expressed a lack of confidence in guidance. Systematic reviews reported a wide range of effect sizes. However, there was a high degree of indirectness and heterogeneity in methods and findings. To produce transparent guidance, those for whom guidance is intended should have evidence of effect where this is available.

Guideline authors should reflect these outcomes in their recommendations, clearly balancing both the benefits and harms of recommending face masks to prevent COVID-19.