The prevalence of dementia in a Portuguese community sample: a 10/66 Dementia Research Group study

Abstract

BackgroundDementia imposes a high burden of disease worldwide. Recent epidemiological studies in European community samples are scarce. In Portugal, community prevalence data is very limited. The 10/66 Dementia Research Group (DRG) population-based research programmes are focused in low and middle income countries, where the assessments proved to be culture and education fair. We applied the 10/66 DRG prevalence survey methodology in Portugal, where levels of illiteracy in older populations are still high.MethodsA cross-sectional comprehensive one-phase survey was conducted of all residents aged 65 and over of two geographically defined catchment areas in Southern Portugal (one urban and one rural site). Nursing home residents were not included in the present study. Standardized 10/66 DRG assessments include a cognitive module, an informant interview and the Geriatric Mental State-AGECAT, providing data on dementia diagnosis and subtypes, mental disorders including depression, physical health, anthropometry, demographics, disability/functioning, health service utilization, care arrangements and caregiver strain.ResultsWe interviewed 1405 old age participants (mean age 74.9, SD = 6.7 years; 55.5% women) after 313 (18.2%) refusals to participate.The prevalence rate for dementia in community-dwellers was 9.23% (95% CI 7.80–10.90) using the 10/66 DRG algorithm and 3.65% (95% CI 2.97–4.97) using DSM-IV criteria. Pure Alzheimer’s disease was the most prevalent dementia subtype (41.9%). The prevalence of dementia was strongly age-dependent for both criteria, but there was no association with sex.ConclusionsDementia prevalence was higher than previously reported in Portugal. The discrepancy between prevalence according to the 10/66 DRG algorithm and the DSM-IV criteria is consistent with that observed in less developed countries; this suggests potential underestimation using the latter approach, although relative validity of these two approaches remains to be confirmed in the European context. We improved the evidence base to raise awareness and empower advocacy about dementia in Portugal, so that the complex needs of frail older people may be met in better ways.

The prevalence of late-life depression in a Portuguese community sample: A 10/66 Dementia Research Group study

“…Having reported dementia prevalence estimates (Gonçalves-Pereira et al, 2017), in this paper we focus on depression.…”

“…The full array of measures and corresponding details may again be found elsewhere (Gonçalves-Pereira et al, 2016;Prince et al, 2007). In short, we used: 1) the GMS, a semi-structured clinical mental state interview for older people, supported by AGECAT, a diagnostic algorithm based on clinical principles, identifying organicity (probable dementia), depression, anxiety and psychosis (Copeland et al, 1986); the GMS has been extensively validated worldwide (Copeland et al, 2002), including in populations with low education levels (Prince et al, 2004) as still displayed by a significant proportion of Portuguese elders (Gonçalves-Pereira et al, 2017); 2) a cognitive test battery, including e.g., the Community Screening Instrument for Dementia (CSI'D'); 3) a brief physical and neurological examination; 4) demographic and risk factor assessments, including the self-reported number of household assets (e.g. television, fridge/freezer, plumbed bathroom); 5) informant interview including further explorations or the validation of information regarding the participant (i.e.…”

“…The population aged 65 years and older has grown from 16.4% to 19.0% between 2001 and 2011 in Portugal (INE -Instituto Nacional de Estatística, 2012) and it is therefore important to have accurate estimates for the prevalence of mental health conditions in Portuguese older people. In this context, we applied the validated 10/66 Dementia Research Group (DRG) protocols for the first time in Europe (Gonçalves-Pereira et al, 2017). Here we report findings on the prevalence of depression according to a variety of methods, including the Geriatric Mental State (GMS) (Copeland et al, 1986) generated criteria, which may better fit the assessment of depression in older age.…”

“…A standardized operating procedures manual, covering training and field procedures, is available at http://www.alz.co.uk/1066/. Our recent implementation of the 10/66 DRG prevalencestudy protocols attempted to overcome the insufficiencies of community epidemiological research in Portuguese older people (Gonçalves-Pereira et al, 2016), and results regarding dementia prevalence have been published (Gonçalves-Pereira et al, 2017). However, 10/66 DRG studies have not been confined to dementia.…”

“…As reported in detail elsewhere (Gonçalves-Pereira et al, 2017), two catchment areas were mapped, one within Fernão Ferro, the other within Mora/Cabeção, in the south of Portugal. Fernão Ferro is an urban setting, with low and middle class residents.…”