Mortality from dementia in a community-dwelling Brazilian population.

BACKGROUND

The influence of dementia on mortality has not yet been reported for a Latin American country.

OBJECTIVES

To evaluate the influence of dementia on mortality of a community-dwelling elderly population in Brazil, and to verify the extent to which the diagnosis of dementia is reported on death certificates.

METHODS

A cohort of 1,656 individuals, aged 65 and over, was screened for dementia at their domiciles, in 1997. The same population was re-evaluated in 2000, and information on deaths was obtained from relatives and from the municipal obituary service. Kaplan-Meier curves were used for the survival analysis, and the mortality risk ratio (MMR) was calculated using Cox proportional hazards models.

RESULTS

We obtained data from 1,393 subjects, corresponding to 84.1% of the target population. The number of deaths was 58 (51.3%) among the patients with dementia and 163 (12.7%) among those without dementia in 1997 (p <0.0001). Dementia and Alzheimer's disease (AD) decreased survival, with hazards ratios of 5.16 [95% Confidence Interval (CI): 3.74-7.12] for dementia and 4.76 (95% CI: 3.16-7.18) for AD. The Cox proportional hazards model identified dementia (MMR=3.92, 95% CI: 2.80-5.48) as the most significant predictor of death, followed by age, history of stroke, complaints of visual impairment and heart failure and by severe arterial hypertension in the baseline evaluation. Dementia and/or AD were mentioned in only 12.5% of the death certificates of individuals with dementia.

CONCLUSIONS

Dementia causes a significant decrease in survival, and the diagnosis of dementia is rarely reported on death certificates in Brazil.