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Model mis‐specification and overestimation of the intraclass correlation coefficient in cluster randomized trials
Author(s) -
Giraudeau Bruno
Publication year - 2005
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.2260
Subject(s) - intraclass correlation , statistics , cluster (spacecraft) , correlation coefficient , econometrics , correlation , randomized controlled trial , mixed model , mathematics , medicine , computer science , psychometrics , geometry , programming language
Intraclass correlation coefficient (ICC) estimates must be provided when reporting the results of a cluster randomized trial. This study demonstrates that estimating this parameter with one‐way ANOVA and an underlying mixed‐effects statistical model leads to biased estimates. The bias depends on the effect size of the studied treatment. Copyright © 2005 John Wiley & Sons, Ltd.