Table 2.
Study characteristics of mask use in health care workers to prevent viral respiratory tract infections
| RCT (CLUSTER: YES OR NO) | COUNTRY, SETTING | POPULATION (AGE) | SAMPLE SIZE ENROLLED (ANALYZED) | CLUSTERS (RANDOMIZED) | INTERVENTIONS | WHO WORE THE MASKS | MASK USE RECOMMENDATION | ADHERENCE |
|---|---|---|---|---|---|---|---|---|
| Jacobs et al,28 2009 (no) | Japan, tertiary care hospital | Health care workers (mean 35.5 y) | 33 (32) | NA | Mask (17), no mask (15) | Health care workers (not sick) | Health care workers wear masks while on hospital property and performing their roles | 84.3% of participants self-reported “full compliance,” with the remaining complying 79% to 99% of the time (applies to both mask use and nonuse) |
| Loeb et al,29 2009 (no) | Canada, tertiary hospitals | Nurses (mean 36 y) | 446 (422) | NA | Surgical masks (212), N95 masks (210) | Nurses | When caring for patients with febrile respiratory illness | All 11 participants allocated to surgical masks wore them when caring for patientsadmitted to unit in droplet precautions for influenza |
| MacIntyre et al,30 2011 (yes) | China, hospital (ED and respiratory wards) | Nurses, doctors, ward clerks (mean 34 y) | 1441 (1441) | Cluster: unit of randomization was hospital (15 hospitals involved, 5 per study arm) | Surgical masks (492), N95 fit-tested masks (461), N95 masks not fit-tested (488) | Health care workers | Every shift (given 3 surgical masks daily or 2 N95 masks daily) | Worn >80% on working days: surgical, 76% (5 h/day); N95 fit, 74% (5.2 h/day); N95 no fit, 68% (4.9 h/day) |
| MacIntyre et al,31 2013 (yes) | China, hospitals (ED and respiratory wards) | Nurses, doctors (mean 33.1 y) | Surgical mask = 572 (572), targeted use of N95 = 561 (516), N95 = 581 (581), total = 1669 (166) | 68 wards at 19 sites | Surgical masks (572), targeted use of N95 masks (516), N95 masks (581) | Nurses, doctors | All the time (surgical masks), as needed (targeted N95 masks), all the time (N95 masks) | 66% for surgical masks, 82% for N95 targeted masks, 57% for N95 masks |
| MacIntyre et al,32 2015 (yes) | Vietnam, hospitals (ED, ICU, ID or respiratory wards, pediatric ward) | Nurse or doctor (mean 36 y) | 1607 (1607) | 74 wards at 14 sites | Surgical masks (580), cloth masks (2-layer cotton) (569), control (458)—“standard practice” of mask use | Nurses or doctors | Surgical masks: all the time on shift; cloth masks: all the time on shift; control: standard practice | Surgical masks 56.6%, cloth masks 56.8%, standard practice 23.6% |
| Radonovich et al,33 2019 (yes) | US, outpatient sites (clinics, primary care clinics, EDs) | Health care personnel (mean 43 y) | 5180 health care personnel seasons = 4051 participants (5180 seasons) | 380 clusters at 137 sites | Surgical masks (2668 person-seasons), N95 masks (2512 person-seasons)—note that 1 person could be in different arms each of the 4 seasons | Those involved in direct patient care | Whenever positioned within 6 ft of a patient with suspected or confirmed respiratory illness | N95: 65.2% always, 24.2% sometimes; surgical: 65.1% always, 25.1% sometimes |
ED—emergency department, ICU—intensive care unit, ID—infectious disease, NA—not applicable, RCT—randomized controlled trial, US—United States.