Foundations of Activity of Daily Living Trajectories of Older Americans.
OBJECTIVE
The disablement process can be viewed conceptually as a progression from disease to impairment to functional limitation and finally disability (frequently operationalized as activity limitation). This article assesses the extent to which early phases of the process are associated with individual-level disability trajectories by age.


METHODS
We use data from seven waves of the Health and Retirement Study, 1998 to 2010, to investigate for individuals aged 65-84 years how baseline sociodemographic characteristics and self-reported disease, pain, and functional limitation (physical, cognitive, or sensory) are related to the dynamics of limitations in activities of daily living (ADLs). Our modeling approach jointly estimates multiperiod trajectories of ADL limitation and mortality and yields estimates of the number of, shapes of, and factors associated with the most common trajectories.


RESULTS
Individual probability of ADL limitation can best be described by three common trajectories. In comparison with disease, pain, and functional limitation, sociodemographic characteristics have weak associations with trajectory group membership. Notably, neither sex nor education is strongly associated with group membership in multivariate models.


CONCLUSIONS
The analysis confirms the importance of the early phases of the disablement process and their relationships with subsequent trajectories of activity limitation.
Washington Office, RAND Corporation, Arlington, Virginia. lmartin@rand.org.
Linda G
LG
Martin
Department of Social and Behavioral Sciences, University of California, San Francisco.
Zachary
Z
Zimmer
Center for Economic and Social Research, University of Southern California, Los Angeles.
Jinkook
J
Lee
D000203:Activities of Daily Living / Q000145:classification* / Q000523:psychology*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D059350:Chronic Pain / Q000523:psychology; D000066492:Cognitive Aging / Q000523:psychology*; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D012959:Socioeconomic Factors; D013223:Statistics as Topic; D014481:United States
Disability; Functional health status; Health disparities; Mortality; Transition models