Over- and under-diagnosis of dementia in ethnic minorities: a nationwide register-based study

OBJECTIVE: Among dementia professionals in several European countries, it is believed that dementia is under-diagnosed and under-treated to a greater extent among ethnic minorities than in the native population. It is unknown whether this belief holds true. The objective of this study was to compare the prevalence of register-based dementia diagnoses in the largest ethnic minority groups in Denmark with the prevalence of register-based dementia diagnoses in the general Danish population. METHODS: By linking the Danish hospital registers with the Danish Civil Registration System, nationwide dementia cases for three main ethnic minorities were identified. Age- and gender-specific prevalence rates for dementia were calculated and compared to previously published data for the general population. RESULTS: The study population consisted of 68 219 persons aged 20 and older. A total of 174 dementia cases were identified. The mean age at diagnosis was 57.7 years (SD = 16.2). Compared to the general population, there was a higher prevalence of dementia among those younger than 60 years, and a markedly lower prevalence of dementia among those 60 years and older. CONCLUSIONS: Dementia is under-diagnosed to a greater extent among ethnic minorities in the age group 60 years and older but is over-diagnosed in the age group younger than 60 years. Several factors may contribute to this pattern, including cultural differences in help-seeking behaviour, and problems in navigating the health-care system. Furthermore, cross-cultural assessment of dementia can be difficult because of language barriers and cultural differences. Copyright © 2010 John Wiley & Sons, Ltd.