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Randomized Controlled Trial
. 2021 Aug 26;18(17):8971.
doi: 10.3390/ijerph18178971.

The Effectiveness of Free Face Mask Distribution on Use of Face Masks. A Cluster Randomised Trial in Stovner District of Oslo, Norway

Atle Fretheim  1 , Ingeborg Hess Elgersma  2 , Fredrik Aaeng Kristiansen  3 , Caroline Rømming Varmbo  4 , Miriam Kristine Salame Olsbø  4 , Iselin Havstein Strand Glover  4 , Martin Flatø  5
Affiliations
Randomized Controlled Trial

The Effectiveness of Free Face Mask Distribution on Use of Face Masks. A Cluster Randomised Trial in Stovner District of Oslo, Norway

Atle Fretheim et al. Int J Environ Res Public Health. .

Abstract

Face masks are recommended as a means of reducing the spread of COVID-19, but there are practically no studies of interventions to increase face mask use. Over three weeks, nine grocery stores in the Stovner District of Oslo were randomly selected each day to have distribution of free face masks outside their entrance. Free face mask distribution increased the proportion of customers wearing a mask by 6.0 percentage points (adjusted, 95% CI 3.5-8.5). Mean mask usage was 91.7% in the control group and 97.1% in the treatment group (pooled SD 5.3%). Practically all those who wore masks had both nose and mouth covered. We conclude that free distribution of face masks increased their use. Similar trials can be conducted within a short period of time.

Keywords: COVID-19; face masks; infection control.

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Conflict of interest statement

C.R.V., M.K.S.O. and I.H.S.G. are employed at the Stovner District administration and played key roles in the implementation of the free face masks scheme.

Figures

Figure 1
Figure 1
Corona hosts at work.
Figure 2
Figure 2
Randomisation procedure.
Figure 3
Figure 3
Observer at work.
Figure 4
Figure 4
Effect size by level of face mask usage in control group.
Figure 5
Figure 5
Effect size by host.
See this image and copyright information in PMC

References

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