Cochrane (7) and the World Health Organization (8) both point out that, for population health measures, we should not generally expect to be able to find controlled trials, due to logistical and ethical reasons, and should therefore instead seek a wider evidence base. This issue has been identified for studying community use of masks for COVID-19 in particular (9). Therefore, we should not be surprised to find that there is no RCT for the impact of masks on community transmission of any respiratory infection in a pandemic.
Zonder randomized control trails geen bewijs voor effectiviteit mondkapjes.
http://www.gezondheidsnieuws.aantreffen.nl/corona-covid19/wetenschappelijk-bewijs-effectiviteit-mondkapjes-steeds-groter/
Er is geen bewijs voor effectiviteit of ineffectiviteit van medische mondkapjes:
While there is a lack of evidence supporting the effectiveness of facemasks, there is similarly a lack of evidence supporting their ineffectiveness.
https://journals.sagepub.com/doi/pdf/10.1177/0141076815583167
Als effectiviteit van medische kapjes niet valt aan te tonen, waarom zouden niet medische kapjes dan wel effectief zijn?