Predictors of mortality in patients with Alzheimer's disease living in nursing homes

Objectives-To identify factors associated with mortality in patients with A lzheimer's disease, and to evaluate whether these factors vary according to severity of cognitive impairment, Methods-Data were from the SAGE database which includes information on all residents admitted between 1992 and 1995 to all Medicare/Medicaid certified nursing homes of five US states. We conducted a longitudinal follow up stu dy (median 23 months) on 9264 patients aged 65 years and above with a diagn osis of Alzheimer's disease. Patient data including demographic characteris tics, dementia severity, comorbidity, and other clinical and treatment vari ables were collected with the Minimum Data Set. Information on death was de rived through linkage to Medicare files. Baseline characteristics were used to predict survival in univariate and multivariate Cox proportional hazard models. Results-Overall mortality rate was 50%, with a first year rate of 25.7%. In creased age (risk ratio (RR) 1.83; 95% confidence interval (95% CI) 1.65-2. 03, for patients 85+ years), male sex (RR 1.81; 95% CI 1.70-1.94), Limitati on in physical function (RR 1.45; 95% CI 1.27-1.66), a condition of malnutr ition (RR 1.31; 95%CI 1.23-1.39), the presence of pressure ulcers (RR 1.24; 95% CI 1.13-1.36), a diagnosis of diabetes mellitus (RR 1.32; 95% CI 1.21- 1.43), and of cardiovascular diseases (RR 1.22; 95% CI 1.14-1.30) were inde pendent predictors of death, regardless of the severity of baseline dementi a. Sensory problems (hearing and vision) and urinary incontinence were asso ciated with increased mortality only among patients with less severe dement ia. The presence of disruptive behaviour, aphasia, and a diagnosis of Parki nson's disease were not related to survival. African-Americans and other mi nority groups were less likely to die relative to white people, Conclusions-Age, sex, functional limitation, and malnutrition seem to be th e strongest predictors of death for patients with Alzheimer's disease in nu rsing homes. Altogether, severity of dementia has no influence on survival, yet the predictive role of certain variables depends on the degree of impa irment. Minority groups have a reduced risk of death relative to white peop le.