5 June 2020.

This Evidence Snapshot found insufficient evidence that masks are effective in reducing transmission among asymptomatic people in community settings. There was a lack of high-level evidence, with small measures of effect found in some studies. However, 10 of the 13 peer reviewed studies held that face masks or coverings may reduce transmission of COVID-19. Six studies recommended facemasks in combination with handwashing and social distancing. Seven studies suggested that masks be worn: early in a pandemic (3 studies), where social distancing is relaxed (1 study), to prevent a second wave (1 study) or where social distancing is not feasible such as on public transport (2 studies). Agency position statements varied.

Citation: Moore G, Rudge S, Jameson B, Du Toit A, Taha H, Jenkin R. The use of masks by asymptomatic people to reduce transmission of COVID-19: an Evidence Snapshot brokered by the Sax Institute (www.saxinstitute.org.au) for the Australian Commission on Safety and Quality in Health Care, 2020.

Date of completion: April 2020