Gender differences in predictors of mortality in nursing home residents with AD

Objective: To evaluate whether the excess mortality in men with AD can be explained by a gender difference in the predictors of mortality. Methods: The authors studied 2,838 men and 6,385 women over 65 years of age with AD admitted, between 1992 and 1995, to 1 of nearly 1,500 nursing homes in five U.S. states (Kansas, Maine, Mississippi, New York, and South Dakota). Resident level data including sociodemographic characteristics, dementia severity, measures of physical disability, comorbidity, and other clinical variables were collected with the Minimum Data Set. Information on death was derived through linkage to Medicare enrollment files; the median follow-up was 23 months. Baseline characteristics were used to predict age at time of death in Cox proportional hazard models. Results: Men with AD had an increased risk of mortality relative to women, adjusted for differences in the distribution of age and race. The most important predictors of death in men were those related to the disease itself. These were the severity of dementia and the occurrence of episodes of delirium. Instead, death among women was associated with measures of disability, namely, impairment in performing the activities of daily living, presence of pressure sores, malnutrition, and comorbidity. Conclusion: These data suggest that the underlying mechanisms for AD may be different in men and women. Future studies of survival and progression of AD need to examine men and women separately.