Ethnic differences in cognition and age in people diagnosed with dementia: A study of electronic health records in two large mental healthcare providers

Objectives: Qualitative studies suggest that people from UK minority ethnic groups with dementia access health services later in the illness than white UK-born elders, but there are no large quantitative studies investigating this. We aimed to investigate interethnic differences in cognitive scores and age at dementia diagnosis. Methods: We used the Clinical Record Interactive Search (CRIS) applied to the electronic health records of two London mental health trusts to identify patients diagnosed with dementia between 2008 and 2016. We meta-analysed mean Mini Mental State Examination (MMSE) and mean age at the time of diagnosis across trusts for the most common ethnic groups, and used linear regression models to test these associations before and after adjustment for age, sex, index of multiple deprivation, and marital status. We also compared percentage of referrals for each ethnic group with catchment census distributions. Results: Compared with white patients (N = 9380), unadjusted mean MMSE scores were lower in Asian (−1.25; 95% CI −1.79, −0.71; N = 642) and black patients (−1.82, 95% CI −2.13, −1.52; N = 2008) as was mean age at diagnosis (Asian patients: −4.27 (−4.92, −3.61); black patients −3.70 (−4.13, −3.27) years). These differences persisted after adjustment. In general, ethnic group distributions in referrals did not differ substantially from those expected in the catchments. Conclusions: People from black and Asian groups were younger at dementia diagnosis and had lower MMSE scores than white referrals.