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

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 messurements 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