Evidence map›Paper›PMID 37196320›Full record

ArticleInternational journal of epidemiology2023

Estimating intra-cluster correlation coefficients for planning longitudinal cluster randomized trials: a tutorial.

Yongdong Ouyang, Karla Hemming, Fan Li, Monica Taljaard

Abstract read
In one paragraph

Article in International journal of epidemiology, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 19 papers.

0numbers the graph read from it
0cells of the map it votes in
19citing papers in PubMed
–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

19 citing papers in PubMed.

  1. Trial
  2. Trial
  3. Evaluation of injury prevention interventions using the stepped wedge cluster randomised trial design: key considerations.Injury prevention : journal of the International Society for Child and Adolescent Injury Prevention · 2026
    Article
  4. Article
  5. Article
  6. Article
  7. Model-robust standardization in stepped wedge cluster randomized trials.Journal of the Royal Statistical Society. Series A, (Statistics in Society) · 2026
    Article
  8. Article
  9. Article
  10. Article
  11. Article
  12. Article
  13. Article
  14. Article
  15. Article
  16. Article
  17. Article
  18. Article
  19. 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

4 authors.

Yongdong OuyangClinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.ORCID 0000-0002-8692-2991
Karla HemmingInstitute of Applied Health Research, The University of Birmingham, Birmingham, UK.ORCID 0000-0002-2226-6550
Fan LiDepartment of Biostatistics, Yale School of Public Health, New Haven, CT, USA.ORCID 0000-0001-6183-1893
Monica TaljaardClinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.

Funding

Training Core (I)U54AG063546 · NIA · BROWN UNIVERSITY · PI JOSEPH E. GAUGLER · 2019 to 2026
$125.9M
CIHR ME-2020C3-21072NIA NIH HHS U54 AG063546NIH HHS U54AG063546
6 · The paper itself

Abstract

It is well-known that designing a cluster randomized trial (CRT) requires an advance estimate of the intra-cluster correlation coefficient (ICC). In the case of longitudinal CRTs, where outcomes are assessed repeatedly in each cluster over time, estimates for more complex correlation structures are required. Three common types of correlation structures for longitudinal CRTs are exchangeable, nested/block exchangeable and exponential decay correlations-the latter two allow the strength of the correlation to weaken over time. Determining sample sizes under these latter two structures requires advance specification of the within-period ICC and cluster autocorrelation coefficient as well as the intra-individual autocorrelation coefficient in the case of a cohort design. How to estimate these coefficients is a common challenge for investigators. When appropriate estimates from previously published longitudinal CRTs are not available, one possibility is to re-analyse data from an available trial dataset or to access observational data to estimate these parameters in advance of a trial. In this tutorial, we demonstrate how to estimate correlation parameters under these correlation structures for continuous and binary outcomes. We first introduce the correlation structures and their underlying model assumptions under a mixed-effects regression framework. With practical advice for implementation, we then demonstrate how the correlation parameters can be estimated using examples and we provide programming code in R, SAS, and Stata. An Rshiny app is available that allows investigators to upload an existing dataset and obtain the estimated correlation parameters. We conclude by identifying some gaps in the literature.

Indexed as

Research DesignCluster AnalysisHumansRandomized Controlled Trials as TopicSample Sizeclinical trialscluster autocorrelation coefficientSample sizestatistical powerstepped wedge

Identifiers

PMID37196320
PMCPMC10555741

What OpenQuestion holds

Textmetadata
Read underepoch 390

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.