2017. An Index to Predict Activity of Daily Living Dependence in Elders
Kenneth E Covinksy, MD, MPH, San Francisco VAMC, K Lindquist, San Francisco VAMC, J Hilton,
San Francisco VAMC, RA Dudley,
San Francisco VAMC
Objectives: Develop and validate a risk index that predicts dependence in activities of daily living (ADL) at 2 year followup in elders.
Methods: We studied subjects enrolled in AHEAD, a nationally representative study of elders over age 70. We included 5239 subjects (mean age 77) reporting that they could do each of 5 ADL (bathing, dressing, toileting, transferring, eating) without the assistance of another person at baseline. Our outcome was the need for help (dependence) with at least one of the 5 ADL at 2-years. Predictor variables encompassed several domains: demographics, comorbidities, function, cognitive status, and general health. After dividing subjects into development (n=3245) and validation cohorts (n=1994), we used logistic regression to determine independent predictors of 2-year ADL dependence in the development cohort. We then created a risk index, which we tested in the validation sample.
Results: The 8 independent predictors of 2-year ADL dependence were age over 80, diabetes, difficulty walking 3 blocks, difficulty bathing or dressing, need for help with personal finances, difficulty lifting 10 pounds, inability to name the Vice-president, history of falling, and low BMI. In the development sample, rates of ADL dependence in subjects with 0,1,2,3,4, and 5 or more risk factors were 1.3%, 2.8%, 3.8%, 10.1%, 21.6%, and 33.3% respectively (p<.001, roc area=.79). In the validation sample, the rates were 0.7%, 4.3%, 8.7%, 11.3%, 17.8%, and 39.5% (P<.001, roc area=.77).
Conclusions: Using data readily available from patient reports, we validated a risk index that accurately distinguished between subjects at variable risk of ADL dependence.
Impact: In health systems such as VA that serving older patients, preventing ADL dependence is a crucial outcome and a measure of the quality of care. Our index will be useful in identifying patients at highest risk for functional dependence for interventions and for risk adjustment to compare outcomes across different facilities.