Evidence map›Paper›PMID 41728653›Full record

ArticleClinical trials (London, England)2026

Confidence interval estimation for the win probability in cluster randomized trials with hierarchical composite endpoints using win fractions.

Emma Davies Smith, Yun-Hee Choi, Vipul Jairath, Guangyong Zou

Abstract read
In one paragraph

Article in Clinical trials (London, England), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing 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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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.

Emma Davies SmithCenter for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA.ORCID 0000-0001-8200-7908
Yun-Hee ChoiEpidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
Vipul JairathEpidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
Guangyong ZouEpidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.

Funding

BIOSTATISTICS/EPIDEMIOLOGY TRAINING GRANTS IN AIDST32AI007358 · NIAID · HARVARD UNIVERSITY (SCH OF PUBLIC HLTH) · PI Michael David Hughes · 1989 to 2026
$12.4M
NIAID NIH HHS T32 AI007358
6 · The paper itself

Abstract

Background/AimsCluster randomized trials with multiple endpoints feature complex correlation structures. Estimating treatment effects in a meaningful way that respects differences in scale and clinical importance is challenging. Pairwise comparison methods address these challenges by constructing all pairs featuring one treatment and one control participant, then evaluating endpoints in hierarchical order. For cluster randomized trials featuring such a "hierarchical composite endpoint," we develop large-sample confidence interval estimators and hypothesis tests for the nonparametric treatment effect referred to here as the "win probability."MethodsFor each pair of participants (one treated and one control), responses on each endpoint are compared in order of descending clinical importance until it can be determined which participant responded better ("won") or all endpoints are exhausted. Dividing the number of wins attributed to the treatment arm by the total number of "pairwise comparisons" yields a point estimate of the win probability. The win probability can be transformed into alternative effect measures, including the "win difference" and "win odds." A two-stage procedure, or "win fraction" approach, is used to obtain variance estimators for the win probability. Each participant's multivariate response is transformed into a univariate "win fraction," which quantifies the proportion of times they won when compared to all participants in the comparison arm. A working linear mixed model is applied to the win fractions to obtain cluster-adjusted point estimates of the win probability and its variance. Inference proceeds by the central limit theorem. Simulation is used to assess the performance of the proposed estimators for a hierarchical composite endpoint comprised of one binary component (more important) and one continuous component (less important) across a range of cluster trial designs. Performance of an empirical bootstrap estimator is also investigated. A case study using data from the REACT cluster trial demonstrates application of the methods, and corresponding SAS and R code is provided.ResultsSimulation suggests that the nominal 95% coverage probability is well maintained and type I error is controlled. Due to the large-sample nature of our method, confidence intervals may be conservative (over coverage) for fewer than 30 clusters. In comparison, the empirical bootstrap estimator is liberal (under coverage) for all numbers of randomized clusters (up to 50).ConclusionOur win fraction method uses a working linear mixed model to obtain confidence intervals and hypothesis tests which respect coverage and type I error. It is faster than the bootstrap, applicable to multiple components on different scales, bypasses specification of complex correlation matrices, permits adjustment, and can be implemented in existing software.

Indexed as

Endpoint DeterminationRandomized Controlled Trials as TopicCluster AnalysisComputer SimulationConfidence IntervalsData Interpretation, StatisticalHumansModels, StatisticalProbabilityResearch DesignCluster randomized trialshierarchical composite endpointslinear mixed modelnet benefitpairwise comparisonU-statisticswin differencewin oddswin probability

Identifiers

PMID41728653
PMCPMC12931659

What Socratic holds

Textmetadata
LicenceTDM
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 Socratic graph.