A systematic review of the prevalence and covariates of dementia or relative cognitive impairment in the older African-Caribbean population in Britain

Objectives To collate evidence regarding the prevalence and predictors of dementia or relative cognitive impairment in older, African-Caribbean people in Britain, as compared to their white, British peers. Design We conducted a systematic literature review by searching electronic databases, contacting experts in the field and searching the references of identified papers for studies fulfilling our predefined inclusion criteria. They were divided into those measuring the prevalence or incidence of dementia or cognitive impairment, and those investigating risk factors. Each study selected for inclusion, was evaluated by two of the three authors using a standardised checklist and assigned a numerical score for quality. Results Eleven papers fulfilled the selection criteria. Two cross-sectional surveys had calculated prevalence of dementia in a sample of British African-Caribbean people. A further prevalence study had estimated dementia prevalence in a mixed sample of African and African-Caribbean participants. All the comparative studies found an excess of dementia in African-Caribbean people when compared to the indigenous, white population but in one study, this was not statistically significant. Seven studies investigated potential predictive factors for cognitive impairment or cognitive decline. One study investigated the association between hypertension, dementia and country of birth. Conclusions The published research in this area is limited. The available studies consistently indicate an excess of dementia in older African-Caribbean people when compared to the indigenous white population. However, the magnitude of this difference and the associated risk factors are not clear, and warrant further investigation. Copyright (C) 2009 John Wiley & Sons, Ltd.