High Prevalence of Dementia in a Community-Based Survey of Older People from Brazil: Association with Intellectual Activity Rather than Education

Article type: Research Article

Authors: Lopes, Marcos Antonio^{a; *} | Ferrioli, Eduardo^b | Nakano, Eduardo Yoshio^c | Litvoc, Júlio^d | Bottino, Cássio Machado Campos^e

Affiliations: [a] Department of Internal Medicine, Federal University of Santa Catarina, Santa Catarina, Brazil | [b] Faculty of Medicine of Ribeirão Preto, Department of Internal Medicine, University of São Paulo, São Paulo, Brazil | [c] Department of Statistics, University of Brasilia, Brasilia, Brazil | [d] Faculty of Medicine, Department of Preventive Medicine, University of São Paulo, São Paulo, Brazil | [e] Old Age Research Group (PROTER), Faculty of Medicine, Institute of Psychiatry, University of São Paulo, São Paulo, Brazil

Correspondence: [*] Correspondence to: Marcos Antonio Lopes, MD, PhD, Universidade Federal de Santa Catarina, Hospital Universitário, Departamento de Clínica Médica, Rua Maria Flora Pausewang, Campus Universitário, CEP 88040-970, Florianópolis, SC, Brasil. Tel/Fax: +55 48 3721 9014; E-mail: lopes.marcos.ant@gmail.com.

Abstract: Although several surveys have been conducted around the world, few surveys have investigated the prevalence of dementia in Latin America. The aim of this study was to estimate dementia prevalence in a community sample in Ribeirão Preto, Brazil, and to evaluate its distribution across several socio-demographic and clinical characteristics and habits. The population was aged 60 years and older and a representative sample from three different social regions. The screening instruments used in the first phase were the Mini-Mental State Examination, the Fuld Object-Memory Evaluation, the Informant Questionnaire on Cognitive Decline in the Elderly, and the Bayer Activities of Daily Living Scale. In the second phase, the Cambridge Examination was employed to diagnose dementia according to the DSM-IV criteria. The estimate of dementia prevalence was adjusted for screening instrument performance, using the positive and negative predictive values. The data were weighted to compare frequencies, considering the sampling and the non-response effect, and subjected to multivariate analysis. In all, 1.145 elderly subjects were evaluated (mean age: 70.9 years), of whom 63.4% were female and 52.8% had up to 4 years of schooling (participation rates at the first and the second phases were 62.6 and 60%, respectively). The observed and estimated prevalences of dementia were 5.9% and 12.5%, respectively (n = 68). Alzheimer's disease was the main cause (60.3%). Dementia was associated with old age, low education, stroke, absence of arthritis, and not reading books. The estimated prevalence of dementia was higher than the prevalence previously found. Associated factors confirmed the importance of intellectual activities in prevention.

Keywords: Aging, Alzheimer's disease, dementia, epidemiology, prevalence

DOI: 10.3233/JAD-2012-120847

Journal: Journal of Alzheimer's Disease, vol. 32, no. 2, pp. 307-316, 2012