Multidimensional Disability/Mortality Trajectories at Ages 65 and Over: The Impact of State Dependence

Abstract

How dependent is life expectancy atage 65 on one’s degree of disability or specific typesof functional limitations? Are there significant sexdifferences? For closed-cohorts of males and femalesin different disability/functional-status states atage 65, how do their age and disability-specificfunctional statuses evolve with increasing age? Thesequestions are addressed by analyzing multidimensionaldisability/mortality trajectories generated using atwo-component stochastic process model applied tomultivariate longitudinal data from the 1982 to 1994National Long Term Care Surveys. In this model, onecomponent process describes the temporal and agedynamics of a person’s functional state and the otherdescribes the risk of death as a function of aperson’s age and stochastically evolving position inthe functional-status state space. Large differenceswere found in life expectancy among closed cohorts ofpersons who, at age 65, are in one of seven basicdisability/functional-status states, identified by amultivariate analysis. Large differences betweenmales and females in life expectancy for theorigin-specific cohorts were also found. Whilefemales starting in most states tend to live longer,they are not as likely to return to the healthy,nondisabled state – females also tend to go intoinstitutions at a higher rate than males.