Stroke-associated differences in rates of activity of daily living loss emerge years before stroke onset

Objectives To compare typical age-related changes in activities of daily living (ADL) independence in stroke-free adults to long-term ADL trajectories before and after stroke. Study Design, Setting, and Participants Prospective, observational cohort of 18,441 Health and Retirement Study participants who were stroke-free in 1998 and followed through 2008 (average follow-up=7.9 years). Measurements Strokes were assessed with self- or proxy-report of a doctor’s diagnosis and month/year of event. We used logistic regression to compare within-person changes in odds of self-reported independence in 5 ADLs among those who remained stroke free throughout follow-up (n=16,816); those who survived a stroke (n=1,208); and those who had a stroke and did not survive to participate in another interview (n=417). Models were adjusted for demographic and socioeconomic covariates. Results Even prior to stroke, those who later developed stroke had significantly lower ADL independence and were experiencing faster independence losses, compared to similar aged individuals who remained stroke free. Of those who developed a stroke, survivors experienced slower loss of ADL independence compared to those who died. ADL independence declined at the time of stroke and decline continued afterwards. Conclusion Among adults at risk of stroke, disproportionate ADL limitations emerge well before stroke onset. Excess disability among stroke survivors should not be entirely attributed to effects of acute stroke or quality of acute stroke care. Although there are many possible causal pathways between ADL and stroke, the association may alternatively be non-causal. For example, ADL limitations may be a consequence of stroke risk factors (e.g., diabetes) or early cerebrovascular ischemia