MacIntyre & Chughtai3333. MacIntyre CR, Chughtai AA. A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients. Int J Nurs Stud. 2020;108:103629. |
8 RCTs on the use of masks by susceptible exposed healthy persons in the community |
MedLine Embase |
6 RCTs: Surgical masks or PFF2 respirators 2 RCTs: Cloth masks (In 7 RCTs, efficacy of hand hygiene was also tested) |
Laboratory-confirmed influenza Influenza-like illnesses |
No |
Two studies found efficacy of surgical masks and PF2 respirators in subgroup analysis (but not intention-to-tread analysis). Four studies found varied efficacies of masks when combined with hand hygiene intervention, but not for masks alone. Two studies did not find any significant impact of mask use. |
|
5 RCTs on the use of masks by sick persons |
|
All studies involved use of surgical masks |
Laboratory-confirmed influenza Influenza-like illnesses Seasonal coronavirus |
No |
One study found efficacy of masks. One study found efficacy associated with adherence, but not in intention-to-treat analysis. Three studies found no impact of mask use. |
Liang et al.3434. Liang M, Gao L, Cheng C, Zhou Q, Uy J, Heiner K, et al. Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis. Travel Med Infect Dis. 2020;36:101751. [published online ahead of print, 2020 May 28] |
5 RCTs 3 observational studies All studies listed above involved use by susceptible exposed persons in the community |
PubMed, Web of Science, Cochrane Library Chinese National Knowledge Infrastructure (CNKI) VIP (Chinese) database |
Even though some studies included other interventions, only the isolated impact of mask use was analysed. 6 out of 8 studies included involved the use of surgical mask. |
Laboratory-confirmed respiratory virus infection |
Yes |
Even though only three studies found protective impact, the meta-analysis found an overall risk ratio [RR] of 0.43 (95%confidence interval [CI], 0.36-0.79). The findings suggest an average 47% protection. |
Chout et al.3535. Chou R, Dana T, Jungbauer R, Weeks C, McDonagh MS. Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings: A Living Rapid Review. Ann Intern Med. 2020;M20-3213. [published online ahead of print, 2020 Jun 24] |
12 RCTs 3 observational studies |
Multiple electronic databases, including the World Health Organization COVID-19 database and medRxiv preprint server |
Use of masks (mostly surgical) |
RCTs: Laboratory-confirmed influenza, Influenza-like illnesses Observational: SARS-1, MERS, SARS-Cov-2 |
No (but rigorous analysis of quality of evidence and biases conducted) |
1 out of 12 RCTs found some evidence for protection against respiratory viruses. Observational studies supported some protection against SARS-1 and MERS, but evidence for SARS-Cov-2 is still lacking. |
Chu et al.3636. Chu DK, Akl EA, Duda S, Solo K, Yaacoub S, Schünemann HJ, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. Lancet. 2020;395(10242):1973-87. |
No RCT 3 observational studies |
MEDLINE, PubMed, Embase, CINAHL the Cochrane Library, COVID-19 Open Research Dataset Challenge, COVID-19 Research Database (WHO), Epistemonikos EPPI Centre living systematic map of the evidence, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, (also relevant documents on the websites of governmental and other relevant organisations, reference lists of included papers, and relevant systematic reviews) |
Several nonpharmaceutical interventions were analyzed, but only masks were of interest to our review. In all studies relevant to this review (i.e., studies in the community setting), the overall use of masks (regardless of mask type) is analyzed |
All comparative studies focused on SARS-1(No study focusing on MERS or COVID-19) |
Yes |
2 studies found protective effect of mask use. The meta-analysis found overall RR of 0.56 (95%CI, 0.40-0.79). Average protection of 44%. |