MODELING DEVELOPMENT OF SLEEP-WAKE BEHAVIORS - I - USING THE MIXED GENERAL LINEAR-MODEL

The purpose of this paper is to demonstrate the use of the mixed gener al linear model (MixMod) for modeling development of sleep-wake behavi ors in preterm infants. The mixed general linear model allows the conc urrent identification of both group and individual developmental patte rns in longitudinal data sets with inconsistently timed data, irregula rly timed data, and randomly missing values. This statistical techniqu e is well suited to data from preterm infants because these infants en ter and leave longitudinal studies at varying times depending on their health status. One sleep organizational variable-the regularity of re spiration inquiet sleep-obtained from a study of 37 preterm infants wa s used as an example. Seven infant characteristics were used as covari ates. The, various steps involved in conducting a mixed model analysis of this variable are illustrated. The strengths and limitations of th is technique are discussed. (C) 1998 Elsevier Science Inc.