Abstract
Investigators have identified varying trajectories of disability before death, but it is unclear if disability trajectories among decedents and survivors differ among older adults.
We examined self-reported disability in walking a quarter mile at 6-month intervals beginning 3 years before death among 1020 decedents in the Health, Aging and Body Composition Study (Health ABC). Survivors matched for age and gender were identified and self-reports for each pair were tracked over the same 3-year period (total n=2040). Survivor and decedent reports of disability over the 6 assessments were compared using mixed models to calculate the odds of disability for each group adjusted for race, site (Memphis vs. Pittsburgh), and time. In a sensitivity analysis, we assumed that respondents missing self-report status were disabled.
Decedents increased in disability from 48.6% 3 years before death to 78.1% 6 months before death. Among survivors, disability increased from 32.3% to 43.6%. In a logistic regression model the odds of having disability showed a significant month by group (decedents vs. survivors) interaction (p < .0001). The monthly increase in odds of having disability was 6.3% among decedents compared to 2.6% among survivors. The two groups did not differ in volatility, that is, switching between disabled and non-disabled status; but African-American respondents showed greater volatility than whites (p < .0001).
Trajectories of self-reported disability differ between survivors and decedents. Older adults who died after 3 years were more disabled at the start of follow-up and also had a greater risk of increasing disability over each subsequent 6-month assessment.