Masks reduce the risk of respiratory infections

In a new study, researchers at the Norwegian Institute of Public Health (NIPH) have seen clear results that confirm masks have a protective effect against infection.

‘Previous international studies on face masks
have suggested a correlation between mask usage and increased protection
against respiratory infections, but many of these studies are small and have
not provided conclusive answers,’ NIPH
writes on their website.

Researchers at NIPH now believe their new
study, published in the renowned medical journal BMJ, confirms
that masks have a protective effect against respiratory infections.

Fewer sick in the mask group

The study was conducted between February 10
and April 27, 2023. 4,647 people from across Norway participated, with half being
asked to wear masks in crowded places outside their home.

“Since this is a randomised study, other
factors will be evenly and randomly distributed due to the number of
participants. Over 4,000 participants is enough to be quite certain of the
effect of face masks found in this study,” says Runar Solberg.

He is a researcher at NIPH’s Center for Epidemic
Interventions Research.

The results showed that fewer in the mask-wearing
group became ill during the period. 9 per cent of the participants in the mask
group developed symptoms of respiratory infection during the period, compared
to 12 per cent in the control group.

“In practice, this means 3,300 fewer cases
of infection per 100,000 inhabitants in Norway,” says Solberg.

May be sensible to use masks

A potential source of error is that there was
some dropout during the study, writes NIPH.

In the mask-wearing group, 13.7 per cent of
participants did not complete the entire study, while in the control group,
20.7 per cent dropped out.

Researchers still believe that the study
shows clear results confirming that mask use can help prevent respiratory infections.

“What we now know about the protective
effect of using masks suggest that it may be sensible to use them, along with
following general infection control advice such as maintaining distance,
especially if there is a high level of infection in circulation,” says Solberg.

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Translated by Alette Bjordal Gjellesvik

Read the Norwegian version of this article on forskning.no

Reference:

Solberg et al. Personal protective effect of wearing surgical face masks in public spaces on self-reported respiratory symptoms in adults: pragmatic randomised superiority trial. BMJ, 2024. DOI: 10.1136/bmj-2023-078918