Cognitive function in UK community-dwelling African Caribbean and white elders: a pilot study

In recent years there has been interest in risk of cognitive impairment and dementia in populations of African origin. Little is known about this risk in older African Caribbean residents in the UK. One difficulty is lack of consensus over an adequate cognitive test battery for this community. Forty-five African Caribbean and 45 age and gender matched white community residents were recruited by household enumeration of an inner London electoral ward. These participants were administered the MMSE during a screening interview. Where possible, this was followed up by tests from the CERAD and CAMCOG neuropsychological batteries, a medical examination, and a structured interview with an informant. Based on these data, a psychiatrist blind to ethnicity independently rated 86 of these participants (41 of the African Caribbeans, all 45 of the whites) as cognitively normal, cognitively impaired, or demented. Of 41 African Caribbeans, 18 (44%) were rated as cognitively normal, 9 (22%) were rated as cognitively impaired, and 14 (34%) were rated as demented. Of the 45 whites, 39 (87%) were rated as cognitively normal, 4 (9%) were rated as cognitively impaired, and 2 (4%) were rated as demented. African Caribbeans scored significantly lower than whites in most cognitive test scores, which was not accounted for by their lower educational and occupational attainment, or their higher frequency of cardiovascular risk factors. African Caribbean elders in the UK appear to be at high risk of cognitive impairment and dementia. However, the influence of potential confounding factors such as socio-economic position and ill-health, and the effect of cultural test bias, cannot be ruled out.