Evidence map›Paper›PMID 21477136›Full record

Trial reportInfluenza and other respiratory viruses2011

A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers.

Chandini Raina MacIntyre, Quanyi Wang, Simon Cauchemez, Holly Seale, Dominic E Dwyer, Peng Yang, Weixian Shi, Zhanhai Gao, Xinghuo Pang, Yi Zhang and 4 more

Registry-linked trialOpen access · bronzeAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Influenza and other respiratory viruses, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT05036941 (A Cluster Randomized Trial of Two Mask Systems), which is not on this map. Cited by 136 papers, 28 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
136citing papers in PubMed, 28 pooled it
9.0field-weighted citation impact, top 2% of its field
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.

NCT05036941 naunknown statusnot on this mapstarted 2021, after this paper: background citation

A Cluster Randomized Trial of Two Mask Systems (Acteev™ N95 + Acteev™ Fabric Masks vs. Standard N95 + Fabric Masks During Shifts & in Community) in Preventing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) in HCWs

TypeinterventionalSponsorAscend Performance MaterialsRan2021 to 2022Enrolled1,600ConditionsSARS CoV-2 Infection, Influenza -Like IllnessArmsActeev™ Masks, Comparison Masks
3 · Its place in the literature

Who cites it

136 citing papers in PubMed, 28 syntheses or guidelines pooled it, 265 citations in OpenAlex.

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  16. Guidelines: Anaesthesia in the context of COVID-19 pandemic.Anaesthesia, critical care & pain medicine · 2020
    Guideline
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76 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

14 authors at 4 institutions in 3 countries.

Chandini Raina MacIntyreSchool of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales, Sydney, Australia. r.macintyre@unsw.edu.au
Quanyi Wang
Simon Cauchemez
Holly Seale
Dominic E Dwyer
Peng Yang
Weixian Shi
Zhanhai Gao
Xinghuo Pang
Yi Zhang
Xiaoli Wang
Wei Duan
Bayzidur Rahman
Neil Ferguson
Beijing Center for Disease Prevention and Control · CNUNSW Sydney · AUImperial College London · GBWestmead Hospital · AU

Funding

Medical Research Council
6 · The paper itself

Abstract

backgroundWe compared the efficacy of medical masks, N95 respirators (fit tested and non fit tested), in health care workers (HCWs).

methodsA cluster randomized clinical trial (RCT) of 1441 HCWs in 15 Beijing hospitals was performed during the 2008/2009 winter. Participants wore masks or respirators during the entire work shift for 4 weeks. Outcomes included clinical respiratory illness (CRI), influenza-like illness (ILI), laboratory-confirmed respiratory virus infection and influenza. A convenience no-mask/respirator group of 481 health workers from nine hospitals was compared.

findingsThe rates of CRI (3·9% versus 6·7%), ILI (0·3% versus 0·6%), laboratory-confirmed respiratory virus (1·4% versus 2·6%) and influenza (0·3% versus 1%) infection were consistently lower for the N95 group compared to medical masks. By intention-to-treat analysis, when P values were adjusted for clustering, non-fit-tested N95 respirators were significantly more protective than medical masks against CRI, but no other outcomes were significant. The rates of all outcomes were higher in the convenience no-mask group compared to the intervention arms. There was no significant difference in outcomes between the N95 arms with and without fit testing. Rates of fit test failure were low. In a post hoc analysis adjusted for potential confounders, N95 masks and hospital level were significant, but medical masks, vaccination, handwashing and high-risk procedures were not.

interpretationRates of infection in the medical mask group were double that in the N95 group. A benefit of respirators is suggested but would need to be confirmed by a larger trial, as this study may have been underpowered. The finding on fit testing is specific to the type of respirator used in the study and cannot be generalized to other respirators.

trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: ACTRN12609000257268 (http://www.anzctr.org.au).

Indexed as

AdultFemaleHumansInfection ControlMaleMasksOccupational ExposurePersonnel, HospitalProspective StudiesRespiratory Protective DevicesRespiratory Tract Infections

Identifiers

PMID21477136
PMCPMC4941587
OpenAlexW1557580289

What OpenQuestion holds

Textmetadata
Read underepoch 390

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.