THE TIMING OF CHANGE - PATTERNS IN TRANSITIONS IN FUNCTIONAL STATUS AMONG ELDERLY PERSONS

Data from the Longitudinal Study on Aging (LSOA) were analyzed to desc ribe the heterogeneity of functional status transitions over 2-years ( single-state model), and to explore whether changes irt status ill the previous two to four year period enhance the prediction of a subseque nt transition (two-state model). Multivariate logistic regression with a robust estimate of variance was used to analyze a 7-category nomina l response of: functional status (4 levels), institutionalization, dea th, and missing. Weighted percentages for functional status transition s and stability (unchanged status) showed that unchanged or improved f unctioning were at least as common as death or worsened functional sta tus. Initial disability level, morbidities, and self-rated health were the strongest predictors of disability status after 2-years. The two- state model revealed that a previous transition (positive or negative) increases the risk for a subsequent transition, independent of initia l disability level. The predictive and explanatory quality of the two- state model is substantially improved over single-state models, partic ularly from its ability to identify subgroups of individuals with mark ed functional status instability.