Dementia risk in a diverse population: A single-region nested case-control study in the East End of London.

Background

Most evidence about dementia risk comes from relatively affluent people of White European ancestry. We aimed to determine the association between ethnicity, area level socioeconomic deprivation and dementia risk, and the extent to which variation in risk might be attributable to known modifiable clinical risk factors and health behaviours.

Methods

In this nested case-control study, we analysed data from primary care medical records of a population of 1,016,277 from four inner East London boroughs, United Kingdom, collected between 2009 and 2018. The outcome measures were odds ratios for dementia according to ethnicity and deprivation, before and after the addition of major modifiable risk factors for dementia; and weighted population attributable risk for comparison between individual risk factors.

Findings

We identified 4137 dementia cases and 15,754 matched controls (mean age for cases and controls were 80·7 years, (SD 8·7); 81·3 years, (SD 8·9) respectively, range 27-103). Black and South Asian ethnicity were both associated with increased risk of dementia relative to White (odds ratios [95% CI]: Black 1·43 [1·31-1·56]; South Asian 1.17 [1·06-1·29]). Area-level deprivation was independently associated with an increased risk of dementia in a dose-dependent manner. Black and South Asian ethnicity were both associated with a younger age at dementia diagnosis (odds ratios [95%CI]: 0·70 [0·61-0·80] and 0·55 [0·47-0·65], respectively). Population attributable risk was higher for ethnicity (9·7%) and deprivation (11·7%) than for any established modifiable risk factor in this population.

Interpretation

Ethnicity and area-level deprivation are independently associated with dementia risk in East London. This effect may not be attributable to the effect of known risk factors.

Funding

Barts Charity (MGU0366).

Informations de copyright

© 2022 The Author(s).

Déclaration de conflit d'intérêts

All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: all authors had financial support from Bart Charity (MGU0366) for the submitted work. Dr. Cuzick reports grants from Barts charity, outside the submitted work. Dr. Giovannoni reports personal fees from AbbVie, grants and personal fees from Biogen, grants and personal fees from Canbex, personal fees from GW Pharma, grants and personal fees from Merck-Serono, grants and personal fees from Novartis, grants and personal fees from Teva, personal fees from Fiveprime, grants and personal fees from Roche, personal fees from Synthon BV, grants and personal fees from Bayer-Schering, personal fees from Eisai, personal fees from Elan, personal fees from Genentech, personal fees from GSK, grants and personal fees from Ironwood, personal fees from Pfizer, grants and personal fees from Genzyme/Sanofi, grants from UCB Pharma, outside the submitted work. Dr. Dobson reports grants from Barts Charity, grants from MS Society of Great Britain, grants from Horne Family Charitable Trust, grants and personal fees from Merck, personal fees from Roche, grants and personal fees from Biogen, personal fees from Teva, personal fees from Sanofi Genzyne, grants from Celgene, personal fees from Janssen, outside the submitted work. Dr. Noyce reports grants from Parkinson's UK, grants from Virginia Kieley benefaction, grants and non-financial support from GE Healthcare, personal fees from Profile, Bial and Britannia, outside the submitted work. Dr. Marshall reports personal fees from GE Healthcare, outside the submitted work. All other authors have no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.