Evidence map›Paper›PMID 33048964›Full record

Trial reportPloS one2020

Facemask against viral respiratory infections among Hajj pilgrims: A challenging cluster-randomized trial.

Mohammad Alfelali, Elizabeth A Haworth, Osamah Barasheed, Al-Mamoon Badahdah, Hamid Bokhary, Mohamed Tashani, Mohammad I Azeem, Jen Kok, Janette Taylor, Elizabeth H Barnes and 9 more

Abstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in PloS one, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers, 7 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
27citing papers in PubMed, 7 pooled it
–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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

27 citing papers in PubMed, 7 syntheses or guidelines pooled it.

  1. Guideline
  2. Pooled it
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  8. Article
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  11. Review
  12. WHO'Frontiers in public health · 2025
    Article
  13. Review
  14. Gurbaxani et al. Respond.American journal of public health · 2024
    Article
  15. Effect of Face Masking on Transmission of SARS-CoV-2.Advances in experimental medicine and biology · 2024
    Article
  16. Review
  17. Review
  18. Article
  19. Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

19 authors.

Mohammad AlfelaliNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-4046-2045
Elizabeth A HaworthMenzies Institute for Medical Research Tasmania, Hobart, Tasmania, Australia.
Osamah BarasheedNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-9335-6019
Al-Mamoon BadahdahNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.
Hamid BokharyMarie Bashir Institute for Infectious Diseases and Biosecurity, School of Life & Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0001-9533-0720
Mohamed TashaniDiscipline of Child and Adolescent Health, The Children's Hospital at Westmead Clinical School, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0003-1669-1494
Mohammad I AzeemNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-4774-9065
Jen KokMarie Bashir Institute for Infectious Diseases and Biosecurity, School of Life & Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-8796-283X
Janette TaylorNSW Health Pathology - Institute for Clinical Pathology and Medical Research, Westmead Hospital and The University of Sydney, Sydney, New South Wales, Australia.
Elizabeth H BarnesNHMRC Clinical Trials Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.
Haitham El BashirRehabilitation Department, Al Jalila Children Specialty Hospital, Dubai, United Arab Emirates.
Gulam KhandakerDiscipline of Child and Adolescent Health, The Children's Hospital at Westmead Clinical School, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia.
Edward C HolmesMarie Bashir Institute for Infectious Diseases and Biosecurity, School of Life & Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0001-9596-3552
Dominic E DwyerMarie Bashir Institute for Infectious Diseases and Biosecurity, School of Life & Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0002-7163-2844
Leon G HeronNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.
Godwin J WilsonDepartment of Laboratory Medicine, Hamad Medical Corporation, Doha, Qatar.ORCID 0000-0003-0162-9591
Robert BooyNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.
Harunor RashidNational Centre for Immunisation Research and Surveillance, The Children's Hospital at Westmead and The University of Sydney, Sydney, New South Wales, Australia.ORCID 0000-0003-2286-5139
Hajj Research Team

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIn this large-scale cluster-randomized controlled trial (cRCT) we sought to assess the effectiveness of facemasks against viral respiratory infections. METHODS AND

resultsOver three consecutive Hajj seasons (2013, 2014, 2015) pilgrims' tents in Makkah were allocated to 'facemask' or 'no facemask' group. Fifty facemasks were offered to participants in intervention tents, to be worn over four days, and none were offered to participants in control tents. All participants recorded facemask use and respiratory symptoms in health diaries. Nasal swabs were collected from the symptomatic for virus detection by reverse transcription polymerase chain reaction. Clinical symptoms and laboratory results were analyzed by 'intention- to-treat' and 'per-protocol'. A total of 7687 adult participants from 318 tents were randomized: 3864 from 149 tents to the intervention group, and 3823 from 169 tents to the control group. Participants were aged 18 to 95 (median 34, mean 37) years, with a male to female ratio of 1:1.2. Overall, respiratory viruses were detected in 277 of 650 (43%) nasal/pharyngeal swabs collected from symptomatic pilgrims. Common viruses were rhinovirus (35.1%), influenza (4.5%) and parainfluenza (1.7%). In the intervention arm, respectively 954 (24.7%) and 1842 (47.7%) participants used facemasks daily and intermittently, while in the control arm, respectively 546 (14.3%) and 1334 (34.9%) used facemasks daily and intermittently. By intention-to-treat analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (odds ratio [OR], 1.4; 95% confidence interval [CI], 0.9 to 2.1, p = 0.18) nor against clinical respiratory infection (OR, 1.1; 95% CI, 0.9 to 1.4, p = 0.40). Similarly, in a per-protocol analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (OR 1.2, 95% CI 0.9-1.7, p = 0.26) nor against clinical respiratory infection (OR 1.3, 95% CI 1.0-1.8, p = 0.06).

conclusionThis trial was unable to provide conclusive evidence on facemask efficacy against viral respiratory infections most likely due to poor adherence to protocol.

Indexed as

MasksAdolescentAdultAgedAged, 80 and overConfidence IntervalsFemaleHumansMaleMiddle AgedOdds RatioRespiratory Tract InfectionsSaudi ArabiaYoung Adult

Identifiers

PMID33048964
PMCPMC7553311

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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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.