Evidence map›Paper›PMID 26344808›Full record

ArticleJournal of clinical epidemiology2016

Sample size calculations for stepped wedge and cluster randomised trials: a unified approach.

Karla Hemming, Monica Taljaard

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

Article in Journal of clinical epidemiology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 2 registered trials, which are not on this map. Cited by 143 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
143citing papers in PubMed, 2 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.

NCT03243396 nacompletednot on this mapstarted 2018, after this paper: background citation

Building and Sustaining Interventions for Children (BASIC): Task-sharing Mental Health Care in Low-resource Settings

TypeinterventionalSponsorDuke UniversityRan2018 to 2024Enrolled956ConditionsGrief, Post Traumatic Stress Disorder, DepressionArmsTrauma-Focused Cognitive Behavioral Therapy
NCT04029454 nacompletednot on this mapstarted 2020, after this paper: background citation

Neovac 2 Burkina Faso: Impact of the Integration of Hepatitis B Birth Dose Vaccine Into the Infant Immunization Schedule: a Mixed Methods Study Including a Cluster-randomized Trial, an Anthropological Study and an Economic Evaluation

TypeinterventionalSponsorInstitut PasteurRan2020 to 2023Enrolled10,000ConditionsHepatitis BArmsbirth dose vaccination against hepatitis B strategy
3 · Its place in the literature

Who cites it

143 citing papers in PubMed, 2 syntheses or guidelines pooled it.

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83 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

2 authors.

Karla HemmingSchool of Health and Population Sciences, University of Birmingham, Birmingham B15 2TT, UK. Electronic address: k.hemming@bham.ac.uk.
Monica TaljaardClinical Epidemiology Program, Ottawa Hospital Research Institute, 1053 Carling Avenue, Ottawa, Ontario K1Y4E9, Canada; Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.

Funding

Department of Health WMCLAHRC-2014-1Medical Research Council G0800808
6 · The paper itself

Abstract

objectivesTo clarify and illustrate sample size calculations for the cross-sectional stepped wedge cluster randomized trial (SW-CRT) and to present a simple approach for comparing the efficiencies of competing designs within a unified framework. STUDY DESIGN AND

settingWe summarize design effects for the SW-CRT, the parallel cluster randomized trial (CRT), and the parallel cluster randomized trial with before and after observations (CRT-BA), assuming cross-sectional samples are selected over time. We present new formulas that enable trialists to determine the required cluster size for a given number of clusters. We illustrate by example how to implement the presented design effects and give practical guidance on the design of stepped wedge studies.

resultsFor a fixed total cluster size, the choice of study design that provides the greatest power depends on the intracluster correlation coefficient (ICC) and the cluster size. When the ICC is small, the CRT tends to be more efficient; when the ICC is large, the SW-CRT tends to be more efficient and can serve as an alternative design when the CRT is an infeasible design.

conclusionOur unified approach allows trialists to easily compare the efficiencies of three competing designs to inform the decision about the most efficient design in a given scenario.

Indexed as

Sample SizeRandomized Controlled Trials as TopicResearch DesignCluster randomized trialEfficiencyPowerSample sizeStepped wedgeStudy design

Identifiers

PMID26344808
PMCPMC4687983

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.