Generalized reliability estimation using repeated measurements.
The British journal of mathematical and statistical psychology, 59 (Pt 1):
113-31 (May 2006)Mesures de concordància; Online; ICC; Psiquiatria.DOI: 10.1348/000711005X66068
Abstract
Reliability can be studied in a generalized way using repeated measurements. Linear mixed models are used to derive generalized test-retest reliability measures. The method allows for repeated measures with a different mean structure due to correction for covariate effects. Furthermore, different variance-covariance structures between measurements can be implemented. When the variance structure reduces to a random intercept (compound symmetry), classical methods are recovered. With more complex variance structures (e.g. including random slopes of time and/or serial correlation), time-dependent reliability functions are obtained. The effect of time lag between measurements on reliability estimates can be evaluated. The methodology is applied to a psychiatric scale for schizophrenia.