The evidence they had was of such low quality that no solid conclusions could be made from it. What they found in the research may not reflect reality. They are explicit about this and stress the need for better research.

> "There is uncertainty about the effects of face masks. The low to moderate certainty of evidence means our confidence in the effect estimate is limited, and that the true effect may be different from the observed estimate of the effect...There is a need for large, well‐designed RCTs addressing the effectiveness of many of these interventions in multiple settings and populations, as well as the impact of adherence on effectiveness, especially in those most at risk of ARIs."