STUDIES AROUND THE EFFECTIVENESS OF MASKS ARE INCONCLUSIVE
No association of risk mitigation and mask use
No association of disease incidence and mask use
Best case scenario: a reduction of .09 to .6 odds ratio for wearing mask all the time. Even within a hospital setting the use of masks gives little evidence. “Therefore, evidence for mask use versus nonuse and comparing mask types in health care settings remained insufficient. There were no new studies on the effectiveness and safety of mask reuse or extended use.”
A Danish randomized controlled trial with 6000 participants, published in the Annals of Internal Medicine in November 2020, found no statistically significant effect of high-quality medical face masks against SARS-CoV-2 infection in a community setting.
A July 2020 review by the Oxford Centre for Evidence-Based Medicine found that there is no evidence for the effectiveness of face masks against virus infection or transmission.