Variation of the Risk Associated With Potentially Modifiable Risk Factors for Dementia Between Ethnic Groups Within One Country. A Retrospective Cohort Study Using Routinely Collected Health Data in Aotearoa New Zealand.

Introduction: While risk factor prevalence of individual risk factors for dementia varies between ethnic groups in New Zealand (NZ), it is not known whether the effect of these risks is the same in each group.

Methods: This retrospective cohort study identified incident cases of dementia. Cox regression models calculated the hazard ratio for dementia for each of the risk factors, after adjustment for age and sex.

Results: Education, smoking, diabetes, depression, physical activity and social isolation were associated with a 1.13-1.55 times increased risk of dementia. We did not demonstrate an association between dementia risk and hypertension, alcohol, or air pollution. Differences between ethnic groups is suggested but not confirmed due to study power.

Discussion: Differences in dementia prevention potential between ethnic groups in NZ are potentially contributed to by both differential prevalence and risk factor effects. Public health strategies must be tailored for the ethnic populations at most risk.