Predicting time to nursing home placement based on activities of daily living scores--a modelling analysis using data on Alzheimer's disease patients receiving rivastigmine or donepezil.

OBJECTIVE: To quantify the impact of activities of daily living (ADL) scores on the risk of nursing home placement (NHP) in Alzheimer's disease (AD) patients. SETTING: Models predicting NHP for AD patients have depended on cognitive deterioration as the primary measure. However, there is increased recognition that both patient functioning and cognition are predictive of disease progression. METHODS: Using the database from a prospective, randomised, double-blind trial of rivastigmine and donepezil, two treatments indicated for AD, Cox regression models were constructed to predict the risk of NHP using age, gender, ADL and MMSE (Mini-Mental State Examination) scores as independent variables. PARTICIPANTS: Patients aged 50-85 years, with MMSE scores of 10-20, and a diagnosis of dementia of the Alzheimer type. RESULTS: Cox regression analyses indicated that being female, older age, lower ADL score at baseline, and deterioration in ADL all significantly increased the risk of NHP. Over 2 years, risk of NHP increased by 3% for each 1-point deterioration in ADL score independent of cognition. CONCLUSION: Data analyses from this long-term clinical trial established that daily functioning is an important predictor of time to NHP. Further research may be required to confirm whether this finding translates to the real world.