RESUMO
Ageing has occurred in all regions of the world, with impact on neuropsychiatric disorders, particularly dementia. However, previous meta-analysis and reviews have shown high variability in world dementia prevalence rates. OBJECTIVE: The aim of this study was to perform a wide-ranging review of the dementia prevalence studies published in recent years. METHODS: The search was made on Medline, Lilacs and Embase databases for research conducted between 1994 and 2000. The main inclusion criteria were: use of standard diagnostic criteria and investigation of community samples. RESULTS: The final selection included 42 papers, from all continents. The mean prevalence rate of dementia in subjects aged 65 years and older, for continents, ranged from 2.2% in Africa to 8.9% in Europe, and among countries, from 1.3% in India to 14.9% in Spain. However, there was a trend of clustering of the world prevalence rates with the majority of studies reporting rates between 4.2% and 7.2% (≥65 years). Age directly influenced the rates, with a mean prevalence rate of 1.2% (95% CI: 0.8.1.5) for the 65-69 years group and 39.9% (95% CI: 34.4.45.3) for the 90-94 year group, but showing less pronounced influence in the very elderly age group. The urban samples had higher rates, where no significant gender difference was evidenced. CONCLUSION: The age influence over dementia rates apparently leveled off in the very elderly group while a trend toward similar dementia prevalence rates around the world was probably influenced by greater homogeneity in diagnostic criteria.
população idosa vem aumentando em todo o mundo, levando a um impacto nos transtornos psiquiátricos, principalmente os quadros de demência. Contudo, revisões e meta-análises prévias têm mostrado alta variabilidade nas taxas mundiais de prevalência de demência. OBJETIVO: O objetivo deste estudo foi realizar uma ampla revisão de trabalhos recentes de prevalência de demência. MÉTODOS: O levantamento foi feito em três bases de dados, Medline, Lilacs e EMBASE, no período de 1994 a 2000. Os principais critérios de inclusão foram: uso de critérios diagnósticos padronizados e investigação de amostra comunitária. RESULTADOS: A seleção final incluiu 42 artigos, de todos os continentes. A taxa média de prevalência de demência, na idade maior ou igual a 65 anos, entre continentes, variou de 2.2% na África, até 8.9% na Europa, e entre países, de 1.3% na Índia, até 14.9% na Espanha. Contudo, a maioria dos estudos reportou taxas entre 4.2% e 7.2% (≥65 anos). A idade exerceu influência direta sobre as taxas de prevalência, com taxas médias de 1.2% na faixa etária 65-69 anos, e 39.9% na faixa etária 90-94 anos, mostrando, no entanto, um efeito menos pronunciado nos idosos muito idosos. A população de procedência urbana teve taxas significativamente maiores, e não houve diferença significativa entre os sexos. CONCLUSÃO: A influência da idade sobre as taxas de prevalência de demência diminuiu entre os idosos mais "idosos", e a tendência de resultados similares em todo o mundo provavelmente foi influenciada pela homogeneidade nos critérios diagnósticos.
RESUMO
OBJECTIVES: The objectives of this study were to describe the prevalence of neuropsychiatric symptoms of dementia in Alzheimer disease (AD) and cognitively impaired nondemented (CIND) subjects from a community-based Brazilian sample and to correlate these symptoms with severity of cognitive deficits. METHOD: A total of 1,563 randomly selected subjects were evaluated with the following screening tests: Mini-Mental Status Examination, Fuld Object Memory Evaluation, Informant Questionnaire on Cognitive Decline in the Elderly, and Activities of Daily Living-International Scale. Screen positives were submitted to a workup for dementia, physical and neurologic examination, cranial computed tomography or cerebral magnetic resonance imaging, the Cambridge Examination for Mental Disorders, Clinical Dementia Rating Scale (CDR), and the Neuropsychiatric Inventory (NPI). Diagnosis was made according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. RESULTS: Sixty patients with AD, 25 CIND, and 78 healthy elderly subjects were evaluated. Informants reported that 78.33% of patients with AD had one or more neuropsychiatric symptoms. Apathy (53.33%), depression (38.33%), sleep alterations (38.33%), and anxiety (25%) were the most prevalent disturbances in AD subjects. These disturbances were more prevalent in patients with AD than in the comparison group and CIND individuals. In the CIND group, the most frequent neuropsychiatric symptoms were anxiety and sleep alterations (both with 24%) followed by depression (16%). Total NPI scores were significantly different between AD and CIND groups, AD and comparison groups, and CIND and the comparison group. Apathy was the only neuropsychiatric symptom that was significantly different between the groups divided according to the CDR being more frequent in subjects with moderate to severe dementia. CONCLUSIONS: Neuropsychiatric symptoms seem to be as common in patients living in a developing country as they are in demented patients from the developed world. Indeed, the fact that some of our results are similar to other population-based studies may suggest that cultural factors play a minor role in the emergence of these symptoms, at least in a Latin American country like Brazil.
