Evidence map›Paper›PMID 39048132›Full record

Trial reportBMJ (Clinical research ed.)2024

Personal protective effect of wearing surgical face masks in public spaces on self-reported respiratory symptoms in adults: pragmatic randomised superiority trial.

Runar Barstad Solberg, Atle Fretheim, Ingeborg Hess Elgersma, Mette Fagernes, Bjørn Gunnar Iversen, Lars G Hemkens, Christopher James Rose, Petter Elstrøm

Erratum issued Registry-linked trialAbstract readPragmatic Clinical TrialEquivalence Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in BMJ (Clinical research ed.), 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. It is linked to trial NCT05690516 (The Protective Effect of Mask Wearing Against Respiratory Tract Infections), which is not on this map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT05690516 nacompletednot on this map

The Protective Effect of Mask Wearing Against Respiratory Tract Infections: a Pragmatic Randomized Trial

TypeinterventionalSponsorNorwegian Institute of Public HealthRan2023 to 2023Enrolled4,575ConditionsCOVID-19, Respiratory Tract InfectionsArmsWearing face masks
3 · Its place in the literature

Who cites it

5 citing papers in PubMed.

  1. Article
  2. WHO'Frontiers in public health · 2025
    Article
  3. Long-Term Effects of COVID-19 on Chronic Obstructive Pulmonary Disease.International journal of chronic obstructive pulmonary disease · 2025
    Article
  4. Article
  5. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

8 authors.

Runar Barstad SolbergCentre for Epidemic Interventions Research (CEIR), Norwegian Institute of Public Health, Oslo, Norway runar.solberg@fhi.no.ORCID 0009-0004-9843-0654
Atle FretheimCentre for Epidemic Interventions Research (CEIR), Norwegian Institute of Public Health, Oslo, Norway.
Ingeborg Hess ElgersmaCentre for Epidemic Interventions Research (CEIR), Norwegian Institute of Public Health, Oslo, Norway.
Mette FagernesDivision of Infection Control, Norwegian Institute of Public Health, Oslo, Norway.
Bjørn Gunnar IversenDivision of Infection Control, Norwegian Institute of Public Health, Oslo, Norway.
Lars G HemkensPragmatic Evidence Lab, Research Center for Clinical Neuroimmunology and Neuroscience Basel (RC2NB), Basel, Switzerland.
Christopher James RoseCentre for Epidemic Interventions Research (CEIR), Norwegian Institute of Public Health, Oslo, Norway.
Petter ElstrømCentre for Epidemic Interventions Research (CEIR), Norwegian Institute of Public Health, Oslo, Norway.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo evaluate the personal protective effects of wearing versus not wearing surgical face masks in public spaces on self-reported respiratory symptoms over a 14 day period.

designPragmatic randomised superiority trial.

settingNorway.

participants4647 adults aged ≥18 years: 2371 were assigned to the intervention arm and 2276 to the control arm.

interventionsParticipants in the intervention arm were assigned to wear a surgical face mask in public spaces (eg, shopping centres, streets, public transport) over a 14 day period (mask wearing at home or work was not mentioned). Participants in the control arm were assigned to not wear a surgical face mask in public places.

main outcome measuresThe primary outcome was self-reported respiratory symptoms consistent with a respiratory infection. Secondary outcomes included self-reported and registered covid-19 infection.

resultsBetween 10 February 2023 and 27 April 2023, 4647 participants were randomised of whom 4575 (2788 women (60.9%); mean age 51.0 (standard deviation 15.0) years) were included in the intention-to-treat analysis: 2313 (50.6%) in the intervention arm and 2262 (49.4%) in the control arm. 163 events (8.9%) of self-reported symptoms consistent with respiratory infection were reported in the intervention arm and 239 (12.2%) in the control arm. The marginal odds ratio was 0.71 (95% confidence interval (CI) 0.58 to 0.87; P=0.001) favouring the face mask intervention. The absolute risk difference was -3.2% (95% CI -5.2% to -1.3%; P<0.001). No statistically significant effect was found on self- reported (marginal odds ratio 1.07, 95% CI 0.58 to 1.98; P=0.82) or registered covid-19 infection (effect estimate and 95% CI not estimable owing to lack of events in the intervention arm).

conclusionWearing a surgical face mask in public spaces over 14 days reduces the risk of self-reported symptoms consistent with a respiratory infection, compared with not wearing a surgical face mask.

trial registrationClinicalTrials.gov NCT05690516.

Indexed as

COVID-19MasksSARS-CoV-2Self ReportAdultAgedFemaleHumansMaleMiddle AgedNorwayPandemicsRespiratory Tract Infections

Identifiers

PMID39048132
PMCPMC11267995

What OpenQuestion holds

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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.