Preventing COVID - Masks, Meters and Eyewear Save
A Lancet systematic review and meta-analysis provides the basis for physical distancing and the value of making as measures to prevent infection with coronavirus 2 (SARS-CoV-2) or COVID-19.
The analysis included 172 observational studies, no randomised controlled trials and 44 relevant comparative studies involving 25 697 patients. Main points being:
- Transmission of viruses was lower with physical distancing of 1 m or more (n=10 736, pooled aOR 0·18, 95% CI 0·09 to 0·38)
- protection was increased as distance was lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; moderate certainty).
- Face mask use reduced the risk of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34)
- stronger associations with N95 or similar respirators compared with disposable surgical masks or similar reusable cotton masks
- The risk of infection without a mask was 17.4%; but with a face mask was only 3.1%
- Eye protection also resulted in less infection (n=3713; aOR 0·22, 95% CI 0·12 to 0·39)
The authors conclude that randomised trials are needed to better clarify the benefit of these interventions.