Prevalence of “organic brain syndrome” in a Southern European population in two different time periods. The ZARADEMP Project

Background: Comparative studies of dementia in different time periods are quite limited in the international literature, but might be useful to test environmental hypotheses. The aim of this study is to compare the prevalence of “organic brain syndrome”, as a measure of dementia, in the elderly living in the same community in two different time periods and using the same methods. Methods: Representative samples of the elderly in the Zaragoza Study or ZARADEMP0 (n= 1,080), completed the past decade, and now in Wave I of the ZARADEMP Project or ZARADEMP I (n= 4,803) were interviewed. The Geriatric Mental State (GMS) was the main case-finding instrument and the results were analysed using the AGECAT diagnostic package to generate diagnoses. Results: Adjusted, total prevalence of “organic brain syndrome” in individuals aged 65years and older has not varied from the previous decade. It was 8.4% in ZARADEMP I ,and 7.4% in ZARADEMP 0 (prevalence ratio, PR = 0.83; CI 0.65-1.07). Adjusted prevalence among men was lower in ZARADEMP I (3.6%) when compared to ZARADEMP 0(5.5%), although the differences do not reach statistically significance (PR= 0.65; CI 0.41-1.05). However, in support of the working hypothesis, the differences were more marked, and we consider they reach statistically significant proportions in the age group 80-84years.Conclusions: The prevalence of “organic brain syndrome” has not increased from the previous decade. On the contrary, the prevalence tends to be lower in men, and the differences reach statistical significance in the age group 80-84 years. New analysis using diagnostic criteria of dementia in the same sample are required to confirm these findings (AU)

The ZARADEMP Project on the incidence, prevalence and risk factors of dementia (and depression) in the elderly community: I. The context and the objectives

Background and Objectives: The public health dimension of the problem ofdementia and depression in the elderly population is well documented, but epidemiologicaldata are generally considered to be insufficient and, at times, contradictory. This paperidentifies relevant research areas for the ZARADEMP Project, which follows the ZaragozaStudy (or ZARADEMP 0) and is part of both EURODEM and EURODEP Studies.Methods: Review of the literature. Hypotheses emerging in previous studies of thisresearch group.Results: The following relevant objectives to study in relation to dementia (and depression)have been identified: a) potential variations over time in the prevalence rate; b) provisionof reliable estimations of incidence rates, specific for age and gender; c) data aboutthe course and natural history of so called “mild cognitive deficit”; d) association betweenhypothesized risk factors and cases of dementia (and depression) and its most frequentsubtypes; and e) testing of hypotheses related to the overlap between dementia and depressionand, specifically, to what extent depression has an increased risk for DAT. Otherobjectives of the study are also reviewed, in particular the cross-cultural comparison offindings in Zaragoza and in other European cities incorporated in both EURODEM andEURODEP Studies. The importance of maintaining good, contemporary methodologicalstandards is emphasized.Conclusions: A number of relevant research areas in the epidemiology of both dementiaand depression in the elderly have been identified. Case-control studies based on incidentcases of dementia of the Alzheimer’s type (DAT) to adequately assess risk factorsseem particularly timely (AU)

The ZARADEMP Project on the incidence, prevalence and risk factors of dementia (and depression) in the elderly community: II. Methods and first results

Background: There is a pressing need to identify environmental risk factorsof dementia and depression in the elderly.Aims: To describe the methods and first results of the ZARADEMP Project, the firstpsychiatric study to document risk factors in incident cases of dementia (and depression)in a Southern European elderly population.Method: A three-wave (baseline and two follow-up waves) epidemiological study toidentify incident cases of dementia (and depression) was completed in a representativesample population. Valid Spanish versions of case-finding instruments, including theGeriatric Mental State (GMS) were administered by standardized researchers. The incidentcases, diagnosed by a panel of psychiatrists using DSM-IV criteria, will be includedin a case-control study.Results: Response rate was acceptable (63.6% in Wave I, 87’2% in Wave II and 85’8%in Wave III), and 4,803 individuals completed Wave I. Diagnostic agreement was achievedin 91.4% of probable cases presented to the panel, and a total of 146 incident cases ofdementia were identified.Conclusions: We feel confident that modern epidemiological requirements have beenfulfilled and the statistical power in the calculations of risk will be acceptable (AU)