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.