Dementia is one of the main causes of disability later in life, ahead of cancer, cardiovascular disease (CVD), and stroke. Research studies have consistently demonstrated ethnic and geographical differences in the rates of dementia. In an increasingly multicultural society, such as the UK, it is vital that we further our understanding of any ethnic variation in dementia rates, as this would better inform policy makers of not only the clinical care that needs to be delivered but also within health service planning and resource allocation. The purpose of this study is to use a large national clinical database to examine the association between ethnicity and the number of cases of dementia amongst ethnic populations, namely the Asian and Black ethnicity minority groups. We will examine the effects of cardiovascular disease and risk factors in the development of dementia. There continues to be controversy as to whether patients from ethnic minority groups are at an increased risk of developing dementia when compared to White ethnic groups and this study will aim to address this issue. Data from the Clinical Practice Research Datalink (CPRD) database will be used to calculate the number of dementia cases in the UK population and what factors increase the risk of this disease. This would in turn enable us to develop risk calculation tools to predict the risk of dementia that can be adapted to various ethnic groups.
This study will be a retrospective longitudinal cohort study. Data on ethnicity and information on CVD risk factors and CVD outcomes will be examined and analysed. Our outcome of interest will include all those participants with a diagnosis of dementia (which will include Vascular dementia, Alzheimer’s disease, Lewy Body dementia, Mixed Dementia and Parkinson’s Disease dementia) as well as those with probable dementia based on a diagnostic algorithm that will incorporate cognitive test results, blood results and imaging where possible.
We will firstly aim to estimate the prevalence and incidence rates of diagnosed and probable dementia amongst different ethnic groups namely, Asian and Black ethnic minority groups. We will examine data on CVD outcomes and risk factors between these different ethnic groups and compare this with the white Caucasian ethnic group. We will also build regression models to test the association between CVD risk factors and dementia between different ethnic populations. We will use various approaches to correct for confounding including propensity score analysis and examine the representativeness of our sample. A sensitivity analyses will be performed by imputing missing values. Finally, we will aim to validate previously defined risk prediction algorithms for dementia in various ethnic groups. We will use previously published coefficients for each predictor variable and examine baseline recalibration of risk in our population.
To estimate the incidence and prevalence of dementia in the CPRD dataset among different ethnic groups, and to examine the interaction between cardiovascular risk factors and ethnicity in relation to risk of dementia.
Ioanna Tzoulaki - Chief Investigator - Imperial College London
Anita Kulatilake - Corresponding Applicant - Imperial College London
Azeem Majeed - Collaborator - Imperial College London
Lefkos Middleton - Collaborator - Imperial College London
Mahsa Mazidi - Collaborator - Imperial College London
Roger Newson - Collaborator - Imperial College London
HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation