#259 Unmasking the evidence around masks for healthcare workers
- Surgical masks and respirators (N95) appear to provide similar protection against viral infections, with N95 masks having slightly lower, but not statistically different, infection rates in the wearer (~1-2%).
- Cloth masks are less effective than surgical masks (with ~2% more respiratory infections in 4 weeks).
- No randomized controlled trials examined transmission from healthcare workers to others and none examined COVID-19.
- Masks are just one-part of Personal Protective Equipment and transmission precautions.
Reading Tools for Practice Article can earn you MainPro+ CreditsJoin Now
Already a CFPCLearn Member? Log in
- Largest Meta-Analysis:1
|Healthcare worker condition||N95 Masks||Surgical Masks||Statistical Difference|
|Confirmed Viral Respiratory Tract Infection||5.7%||8.3%||No|
- Other Systematic Reviews found similar.2-4
- One RCT (1441 healthcare workers) examined fit-tested N95 versus nonfit-tested N95: No difference.5
- Issues: Multiple outcomes, not Covid-19, overall low risk of infection, intervention only used during working hours, did not examine healthcare workers transfer to patients, other staff or family.
- Clinical Respiratory Infections: 7.6% cloth versus 4.8% surgical masks (borderline statistically different).
- Influenza-like Illness: 2.3% cloth versus 0.2% surgical masks (statistically different).
- Laboratory confirmed viral infection: 5.5% cloth versus 3.3% surgical mask (not statistically different).
- In general, when blocking particles/droplets/microorganisms, N95 are slightly better than surgical masks which are better than cloth masks (which get better with thicker cloth/layers).4,7,8
- Masks, compared to no masks, do help prevent infections (example ~3.5% reduction in clinical respiratory infections in RCTs).3,9
- Wearing a mask might prevent infected healthcare workers, including asymptomatic individuals, from transmitting the disease to others.
- Masks should not be considered as an isolated intervention and should always be used with other measures such as hand hygiene and depending on interaction and patients seen, eye protection, face shields and gowns.
- Public use of masks will be reviewed in an upcoming Tools for Practice.