Prevalence of dementia in a southern European population in two different time periods: the ZARADEMP Project.

OBJECTIVE

To compare the prevalence of dementia in two different time periods and two different studies.

METHOD: Representative, random samples of the elderly (>65 years) in the Zaragoza Study or ZARADEMP-0 (n = 1080) completed the previous decade, and now in Wave I of the ZARADEMP Project or ZARADEMP-I (n = 3715) were interviewed. Standardized measures included the Geriatric Mental State and the History and Aetiology schedule. Cases of dementia were diagnosed according to DSM-IV criteria.

RESULTS

Adjusted, global prevalence of dementia has not varied significantly: it was 5.2% (95% CI = 3.9-6.6) in ZARADEMP-0 and 3.9% (95% CI = 3.3-4.5) in ZARADEMP-I (prevalence ratio = 0.75; 95% CI = 0.56-1.02). However, the prevalence in ZARADEMP-I was significantly lower among men, particularly in all age groups between 70 and 84 years.

CONCLUSION

Stability of the global prevalence of dementia in the elderly population has been documented. However, the decreased prevalence found in elderly men stimulated environmental hypotheses.