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Randomized Controlled Trial
. 2022 Dec 1;176(12):1169-1175.
doi: 10.1001/jamapediatrics.2022.3833.

Effect of Wearing a Face Mask on Hand-to-Face Contact by Children in a Simulated School Environment: The Back-to-School COVID-19 Simulation Randomized Clinical Trial

Michelle Science  1   2   3 , Monica Caldeira-Kulbakas  4 , Rulan S Parekh  5   6 , Bryan R Maguire  7 , Stacie Carroll  8   9 , Samantha J Anthony  5   10 , Ari Bitnun  1   3 , Laura E Bourns  2 , Douglas M Campbell  3   11   12   13 , Eyal Cohen  3   5   14   15   16 , Alison Dodds  17 , Vinita Dubey  18   19 , Jeremy N Friedman  3   20 , Jodi L Greenwood  8   9 , Jessica P Hopkins  2   19   21 , Ryan Imgrund  22 , Daphne J Korczak  23   24 , Thomas Looi  25   26 , Emily Louca  17 , Dominik Mertz  27   28 , John Nashid  29 , Giovanna Panzera  8   9 , Jane E Schneiderman  30   31 , Kevin L Schwartz  2   19   32 , Laurie Streitenberger  33 , Sunayna Vuppal  17 , Catharine M Walsh  3   5   15   17   34 , Peter Jüni  15   35   36 , Clyde T Matava  4   37 ; Back-to-School COVID-19 School Study Group
Collaborators, Affiliations
Randomized Controlled Trial

Effect of Wearing a Face Mask on Hand-to-Face Contact by Children in a Simulated School Environment: The Back-to-School COVID-19 Simulation Randomized Clinical Trial

Michelle Science et al. JAMA Pediatr. .

Abstract

Importance: Wearing a face mask in school can reduce SARS-CoV-2 transmission but it may also lead to increased hand-to-face contact, which in turn could increase infection risk through self-inoculation.

Objective: To evaluate the effect of wearing a face mask on hand-to-face contact by children while at school.

Design, setting, and participants: This prospective randomized clinical trial randomized students from junior kindergarten to grade 12 at 2 schools in Toronto, Ontario, Canada, during August 2020 in a 1:1 ratio to either a mask or control class during a 2-day school simulation. Classes were video recorded from 4 angles to accurately capture outcomes.

Interventions: Participants in the mask arm were instructed to bring their own mask and wear it at all times. Students assigned to control classes were not required to mask at any time (grade 4 and lower) or in the classroom where physical distancing could be maintained (grade 5 and up).

Main outcomes and measures: The primary outcome was the number of hand-to-face contacts per student per hour on day 2 of the simulation. Secondary outcomes included hand-to-mucosa contacts and hand-to-nonmucosa contacts. A mixed Poisson regression model was used to derive rate ratios (RRs), adjusted for age and sex with a random intercept for class with bootstrapped 95% CIs.

Results: A total of 174 students underwent randomization and 171 students (mask group, 50.6% male; control group, 52.4% male) attended school on day 2. The rate of hand-to-face contacts did not differ significantly between the mask and the control groups (88.2 vs 88.7 events per student per hour; RR, 1.00; 95% CI, 0.78-1.28; P = >.99). When compared with the control group, the rate of hand-to-mucosa contacts was significantly lower in the mask group (RR, 0.12; 95% CI, 0.07-0.21), while the rate of hand-to-nonmucosa contacts was higher (RR, 1.40; 95% CI, 1.08-1.82).

Conclusions and relevance: In this clinical trial of simulated school attendance, hand-to-face contacts did not differ among students required to wear face masks vs students not required to wear face masks; however, hand-to-mucosa contracts were lower in the face mask group. This suggests that mask wearing is unlikely to increase infection risk through self-inoculation.

Trial registration: ClinicalTrials.gov Identifier: NCT04531254.

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Conflict of interest statement

Conflict of Interest Disclosures: Mr Imgrund reported nonfinancial support from Canada Strong Masks, outside the submitted work. Dr Korczak reported grants from the Canadian Institutes of Health Research and fees from SickKids, Chair of Child, and Youth Medical Psychiatry Research funds, outside the submitted work. Dr Schwartz reported receiving consulting fees from the Greater Toronto Airports Authority. Dr Jüni reported honoraria to the institution from Amgen, Ava, Fresenius, and grants from Appili Therapeutics to the institution, outside the submitted work; and Dr Jüni serves as unpaid member of the steering group of trials funded by Appili Therapeutics, Abbott Vascular, and Terumo, and has participated in advisory boards and/or consulting for Amgen, Ava, and Fresenius. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. CONSORT Diagram
aClass sizes were capped at 15 students based on anticipated Ontario Ministry of Education guidelines for classroom distancing.
Figure 2.
Figure 2.. Distribution of Number of Hand-to-Face Contacts by Mask Group and Control Group
See this image and copyright information in PMC

References

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