Structure and predictive power of intraindividual variability in health and activity measures

Abstract

Intraindividual variability has been shown in many studies to be well structured over time and capable of predicting a wide range of behaviors. This study provides analyses of weekly variations of health and activity measurements in a sample (N = 52) of elderly persons (mean age = 77.5, SD = 7.2). The three main goals and results entailed: 1. Assessing the reliable nature of a health and an activity factor through a metric invariant confirmatory factor model; 2. Assessing the independence of intraindividual variability from level information and showing that the amount of intra-person variability during the first and second half of data collection correlate very highly; 3. Showing that intraindividual variability information of health and activity scores is superior to level information in predicting mortality.