Evidence map›Paper›PMID 26174515›Full record

ArticleInternational journal of epidemiology2015

Methods for sample size determination in cluster randomized trials.

Clare Rutterford, Andrew Copas, Sandra Eldridge

3 registry-linked trialsAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in International journal of epidemiology, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 3 registered trials, which are not on this map. Cited by 216 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
216citing papers in PubMed, 4 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.

NCT03843957 nacompletednot on this mapstarted 2019, after this paper: background citation

Effectiveness and Implementation of mPATH-CRC: a Mobile Health System for Colorectal Cancer Screening

TypeinterventionalSponsorWake Forest University Health SciencesRan2019 to 2023Enrolled77,145ConditionsColorectal Cancer, Cancer, Rectum Cancer, Colon CancerArmsmPATH-CRC, mPATH-Checkin, "high touch" Implementation strategy, "low touch" Implementation Strategy
NCT04188301 phase2completednot on this mapstarted 2019, after this paper: background citation

Safety and Efficacy of Combination Therapy With Ivermectin, Diethylcarbamazine, and Albendazole (IDA) for Individuals With Onchocerciasis

TypeinterventionalSponsorWashington University School of MedicineRan2019 to 2022Enrolled154ConditionsOnchocerciasisArmsIVM w/ ALB, Single dose of IDA, Three daily doses of IDA
NCT07476716 nanot yet recruitingnot on this mapstarted 2026, after this paper: background citation

The Effect of a Peer-modeled Complex Behavioural Change Intervention on the Cardio-metabolic Health of Women in Mbarara City, Uganda

TypeinterventionalSponsorKU LeuvenRan2026 to 2026Enrolled157ConditionsCardio-metabolic HealthArmsA peer-modelled behavioural change intervention
3 · Its place in the literature

Who cites it

216 citing papers in PubMed, 4 syntheses or guidelines pooled it.

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156 more citing papers are in PubMed but not listed here.

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

3 authors.

Clare RutterfordCentre for Primary Care and Public Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK and c.m.rutterford@qmul.ac.uk.
Andrew CopasHub for Trials Methodology Research, MRC Clinical Trials Unit at University College London, London, UK.
Sandra EldridgeCentre for Primary Care and Public Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK and.

Funding

Medical Research Council MC_UU_12023/29
6 · The paper itself

Abstract

backgroundThe use of cluster randomized trials (CRTs) is increasing, along with the variety in their design and analysis. The simplest approach for their sample size calculation is to calculate the sample size assuming individual randomization and inflate this by a design effect to account for randomization by cluster. The assumptions of a simple design effect may not always be met; alternative or more complicated approaches are required.

methodsWe summarise a wide range of sample size methods available for cluster randomized trials. For those familiar with sample size calculations for individually randomized trials but with less experience in the clustered case, this manuscript provides formulae for a wide range of scenarios with associated explanation and recommendations. For those with more experience, comprehensive summaries are provided that allow quick identification of methods for a given design, outcome and analysis method.

resultsWe present first those methods applicable to the simplest two-arm, parallel group, completely randomized design followed by methods that incorporate deviations from this design such as: variability in cluster sizes; attrition; non-compliance; or the inclusion of baseline covariates or repeated measures. The paper concludes with methods for alternative designs.

conclusionsThere is a large amount of methodology available for sample size calculations in CRTs. This paper gives the most comprehensive description of published methodology for sample size calculation and provides an important resource for those designing these trials.

Indexed as

Randomized Controlled Trials as TopicResearch DesignSample SizeHumansPatient Compliancecluster randomizationdesign effectSample size

Identifiers

PMID26174515
PMCPMC4521133

What OpenQuestion holds

Textmetadata
LicenceCC BY
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.