Understanding ethnic diversity in open dementia neuroimaging datasets

Abstract

Introduction Ethnic differences in dementia are increasingly recognised in epidemiological measures and diagnostic biomarkers. Nonetheless, ethnic diversity remains limited in many study populations Here we provide insights into ethnic diversity in open access neuroimaging dementia datasets. Methods Datasets comprising dementia populations who underwent neuroimaging assessment with available data on ethnicity were included. Statistical analyses of sample and effect sizes were based on the Cochrane Handbook. Results 14 databases were included, with 12 studies of healthy and MCI groups, and 11 of dementia groups. Combining all studies, the largest ethnic group was Caucasian (21,512 participants) with the next most common being Afro-Caribbean (1,960), followed by Asian (780). The smallest effect size detectable within the Caucasian group was 0.03, compared to Afro-Caribbean (0.1) and Asian (0.16). Discussion Our findings quantify the lack of ethnic diversity in openly available neuroimaging dementia datasets. More representative data would facilitate the development and validation of neuroimaging biomarkers relevant across ethnicities.