Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza
4.3. Face masks
Summary of evidence
Ten relevant RCTs were identified for this review and meta-analysis to quantify the efficacy of community-based use of face masks, including more than 6000 participants in total (42-47, 50, 68- 70). Most trials combined face masks with improved hand hygiene, and examined the use of face masks in infected individuals (source control) and in susceptible individuals. In the pooled analysis, although the point estimates suggested a relative risk reduction in laboratory-confirmed influenza of 22% (RR: 0.78, 95% CI: 0.51–1.20, I2=30%, P=0.25) in the face mask group, and a reduction of 8% in the face mask group regardless of whether or not hand hygiene was also enhanced (RR: 0.92, 95% CI=0.75–1.12, I2=30%, P=0.40),
the evidence was insufficient to exclude chance as an explanation for the reduced risk of transmission. Some studies reported that low compliance in face mask use could reduce their effectiveness. A study suggested that surgical and N95 (respirator) masks were effective in preventing the spread of influenza (71).
OVERALL RESULT OF EVIDENCE ON FACE MASKS
1. Ten RCTs were included in the meta-analysis, and there was no evidence that face masks are effective in reducing transmission of laboratory-confirmed influenza.
Summary of considerations of members of the guideline development group for determining the direction and strength of the recommendations
The guideline development group, with the support of the steering group, formulated recommendations that were informed by the evidence presented and took into account quality of evidence, values and preferences, balance of benefits and harms, resource implications, ethical considerations, acceptability and feasibility, as outlined below.
Quality of evidence
There is a moderate overall quality of evidence that face masks do not have a substantial effect on transmission of influenza.
Values and preferences
Face mask use is common to prevent transmission of infections in health care settings around the world, and a widely used measure in some communities, particularly in South-East Asia.
Balance of benefits and harms
There are no major adverse effects of face mask use. There might be issues with allergies in some individuals, and prolonged use of face masks can be uncomfortable or inconvenient.
Resource implications
Reusable cloth face masks are not recommended. Medical face masks are generally not reusable, and an adequate supply would be essential if the use of face masks was recommended. If worn by a symptomatic case, that person might require multiple masks per day for multiple days of illness.
Ethical considerations
There are no major ethical considerations in the use of face masks. Masks may be more culturally acceptable in some locations, and other health behaviours may affect compliance (72).
Acceptability
Face masks are widely used in health care settings to prevent transmission of infections, and are used in the community in some parts of the world (65). They are likely to be acceptable if recommended, particularly in more severe epidemics and pandemics. However, face masks are not appropriate under some circumstances (e.g. during sleep). The guideline development group also considered that compliance may not be high in some areas and populations.
Feasibility
Twenty-eight Member States have included the use of face masks in their national influenza preparedness plan (65). Feasibility can be enhanced by education campaigns to improve usage and compliance. The guideline development group believed that this intervention is feasible, especially for symptomatic individuals.
RECOMMENDATION:
Face masks worn by asymptomatic people are conditionally recommended in severe epidemics or pandemics, to reduce transmission in the community. Disposable, surgical masks are recommended to be worn at all times by symptomatic individuals when in contact with other individuals.
Although there is no evidence that this is effective in reducing transmission, there is mechanistic plausibility for the potential effectiveness of this measure.
Population:
Population with symptomatic individuals; and general public for protection
When to apply:
At all times for symptomatic individuals (disposable surgical mask), and in severe epidemics or pandemics for public protection (face masks)
We cannot prove masks are effective vs the Flu, but wear then any3way ..... you will feel better