Mixed model analysis of censored longitudinal data with flexible random-effects density.

ABSTRACT: Mixed models are commonly used to represent longitudinal or repeated measures data. An additional complication arises when the response is censored, for example, due to limits of quantification of the assay used. While Gaussian random effects are routinely assumed, little work has characterized the consequences of misspecifying the random-effects distribution nor has a more flexible distribution been studied for censored longitudinal data. We show that, in general, maximum likelihood estimators will not be consistent when the random-effects density is misspecified, and the effect of misspecification is likely to be greatest when the true random-effects density deviates substantially from normality and the number of noncensored observations on each subject is small. We develop a mixed model

SUBMITTER: Vock DM 

PROVIDER: S-EPMC3276268 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature