Perceived causes of disability added prognostic value beyond medical conditions and functional status.

ABSTRACT

OBJECTIVE: This study's objective was to determine the incremental benefit of respondent subjective attribution of functional decline beyond relying solely on disease burden in predicting survival. STUDY DESIGN AND SETTINGS A total of 9447 older adults from the Second Longitudinal Study on Aging, a probability sample of community dwelling adults aged 70 or older, were evaluated. Survival was based on status at follow-up interview 3-4 years after baseline interview. Logistic regression was performed using demographic variables and coexisting diseases as a baseline, then adding functional status measures (ADL, IADL) and individual subjective attribution of functional limitation in subsequent models. RESULTS: The predictions improved significantly with the addition of functional status measures (P<0.001) and the individual subjective attribution of functional limitation (P<0.001). For example, the probability of mortality for individuals with cancer was 17.3%, but 28.8% of those with cancer and functional limitations died as did 50% of those with cancer who reported functional limitations attributable to cancer. CONCLUSION: Among persons who can make a specific attribution of their functional limitation, the attribution may have value as a marker of severity of disease and serve as a good predictive measure for mortality, especially in specific illnesses such as cancer.