Cognitive and behavioural predictors of survival in Alzheimer disease: results from a sample of treated patients in a tertiary-referral memory clinic

Objective This study examined the influence of cognitive and non-cognitive factors at the time of diagnosis on the survival of patients with treated probable Alzheimer Disease (AD). Methods Consecutive patients seen at a regional, tertiary-referral clinic completed a battery of cognitive tests and assessments of activities of daily living and neuropsychiatric symptoms. These clinic data were linked with death certificate data for all individuals and survival from diagnosis was calculated. Cox regression models were constructed using the baseline covariates. Results The sample comprised 653 patients (459 women), mean age 77.1?years (SD 7.6, range 4894?years), diagnosed with probable AD and treated with a cholinesterase inhibitor. In the survival analysis, age was a consistently significant predictor of survival with a gender-adjusted hazard ratio of 1.35 (95% CI 1.23, 1.48) for one standard deviation increase in age. Men were at greater risk of death than women (age-adjusted HR 1.44, 95% CI 1.19, 1.73). In a model adjusted for all study variables, Paired-Associate Learning (Cambridge Automated Neuropsychological Test Assessment Battery) and the psychotic factor of the Neuropsychiatric Inventory were significant predictors of survival. Conclusions At diagnosis, in addition to the anticipated impact of age and gender, the presence of psychotic symptoms and poor performance on paired-associate learning are also indicators of poor prognosis. Copyright (C) 2011 John Wiley & Sons, Ltd.