Survival among patients with dementia from a large multi-ethnic population.

Survival among patients with dementia is critical information needed for planning and assessing the overall impact of dementia. Attrition from longitudinal cohorts often limits the confidence in survival estimates. For this study, we examined survival among dementia patients from a large multi-ethnic population with excellent longitudinal follow-up. Subjects were all Baylor Alzheimer's Disease Center patients residing in the greater Houston area at the time of initial diagnosis. Vital status was available for all subjects. We estimated median survival time (Kaplan-Meier) from first symptom onset and from diagnosis, and examined the effects of baseline patient characteristics on survival. Median survival time for patients with any form of dementia was 10.5 years from onset and 5.7 years from diagnosis. Similarly, median survival time for probable Alzheimer disease patients was 11.3 years from onset and 5.7 years from diagnosis. Significant trends of decreasing survival with increasing age group (<70; 70-79, > or = 80) were evident for all dementia patients and for patients with Alzheimer disease. Our findings are consistent with previous studies and provide compelling evidence that survival from onset or diagnosis of dementia depends more on age than any other factor.