Limitation in the activities of daily living (ADLs) is strongly prognostic for mortality. Current ADL assessments based on numbers of limitations (counts) obscure the particular activities limited, thus lacking clinical interpretability.
To examine the independent association of 5 stages of ADL with mortality after accounting for known diagnostic and sociodemographic risk factors.
For five stages (ADL 0 to IV), describing both the severity and pattern of ADLs limited, we estimated unadjusted life expectancies and adjusted associations with mortality using a Cox proportional hazards regression model.
Included were 9,447 persons 70 years of age and older from the second Longitudinal Study of Aging.
1-, 5-, and 10-year survival and time to death.
For those with no ADL limitations, the median life expectancy was 10.6 years compared to 6.5, 5.1, 3.8, and 1.6 years for those at ADL I, II, III, and IV, respectively. The sociodemographic and diagnostic-adjusted hazard of death at 1 year was 5-fold greater at stage IV compared to stage 0 (hazard ratio=5.6; 95% confidence interval, 3.8–8.3). The associations of ADL stage with mortality declined over time, but remained statistically significant at 5 and 10 years.
ADL stage continued to explain mortality risk after adjusting for known risk factors including advanced age, stroke, and cancer. ADL stages might aid clinical care planning and policy as a powerful prognostic indicator particularly of short-term mortality, improving on current ADL measures by profiling activity limitations of relevance to determining community support needs.