Evidence map›Paper›PMID 34197941›Full record

ReviewJournal of clinical epidemiology2021

Cluster randomized trials of individual-level interventions were at high risk of bias.

Christina Easter, Jennifer A Thompson, Sandra Eldridge, Monica Taljaard, Karla Hemming

Abstract readReview
PubMed Full text at PMC Publisher
In one paragraph

Review in Journal of clinical epidemiology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
15citing papers in PubMed, 1 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

15 citing papers in PubMed, 1 synthesis or guideline pooled it.

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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

5 authors.

Christina EasterInstitute of Applied Health Research, University of Birmingham, Birmingham, UK.
Jennifer A ThompsonDepartment of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
Sandra EldridgeCentre for Clinical Trials and Methodology, Queen Mary University of London, London.
Monica TaljaardClinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.
Karla HemmingInstitute of Applied Health Research, University of Birmingham, Birmingham, UK. Electronic address: k.hemming@bham.ac.uk.

Funding

Department of Health SRF-2017-10-002Medical Research Council MR/R010161/1
6 · The paper itself

Abstract

objectivesTo describe the prevalence of risks of bias in cluster-randomized trials of individual-level interventions, according to the Cochrane Risk of Bias tool. STUDY DESIGN AND

settingReview undertaken in duplicate of a random sample of 40 primary reports of cluster-randomized trials of individual-level interventions.

resultsThe most common reported reasons for adopting cluster randomization were the need to avoid contamination (17, 42.5%) and practical considerations (14, 35%). Of the 40 trials all but one was assessed as being at risk of bias. A majority (27, 67.5%) were assessed as at risk due to the timing of identification and recruitment of participants; many (21, 52.5%) due to an apparent lack of adequate allocation concealment; and many due to selectively reported results (22, 55%), arising from a mixture of reasons including lack of documentation of primary outcome. Other risks mostly occurred infrequently.

conclusionMany cluster-randomized trials evaluating individual-level interventions appear to be at risk of bias, mostly due to identification and recruitment biases. We recommend that investigators carefully consider the need for cluster randomization; follow recommended procedures to mitigate risks of identification and recruitment bias; and adhere to good reporting practices including clear documentation of primary outcome and allocation concealment methods.

Indexed as

Biomedical ResearchGuidelines as TopicHumansPublication BiasRandomized Controlled Trials as TopicResearch DesignResearch ReportCluster randomized trialsIndividual-level interventionsRisk of biasSelection bias

Identifiers

PMID34197941
PMCPMC8592576

What OpenQuestion holds

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Registered trials

None linked

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.