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Correlated binomial variates: Properties of estimator of intraclass correlation and its effect on sample size calculation
Author(s) -
Feng Ziding,
Grizzle James E.
Publication year - 1992
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.4780111208
Subject(s) - intraclass correlation , statistics , sample size determination , estimator , mathematics , negative binomial distribution , correlation , moment (physics) , sample (material) , poisson distribution , physics , geometry , classical mechanics , thermodynamics , psychometrics
Abstract In group randomized studies, the sample size calculations are complicated by within group (worksite, community, etc.) correlation. We compare by simulation the moment method and the more standard ANOVA method of estimating the intraclass correlation. We find the former is less biased for a small to moderate number of clusters but the difference disappears when the appropriate degree of freedom is used for the ANOVA estimator. We propose a simulation approach for sample size determination and illustrate it with an example.