Generalized reliability estimation using repeated measurements.
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.
Laenen
Annouschka
A
Hasselt University, Centre for Statistics, Diepenbeek, Belgium. annouschka.laenen@uhasselt.be
Vangeneugden
Tony
T
Geys
Helena
H
Molenberghs
Geert
G
D006801:Humans; D008960:Models, Psychological; D008962:Models, Theoretical; D011584:Psychology / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012559:Schizophrenia