To move or not to move? Exploring the relationship between residential mobility, risk of cardiovascular disease and ethnicity in New Zealand

Residential mobility can have negative impacts on health, with some studies finding that residential mobility can contribute to widening health gradients in the population. However, ethnically differentiated experiences of residential mobility and the relationship with health are neglected in the literature. To examine the relationship between residential mobility, risk of cardiovascular disease (CVD) and ethnicity, we constructed a cohort of 2,077,470 participants aged 30 + resident in New Zealand using encrypted National Health Index (eNHI) numbers linked to individual level routinely recorded data. Using binary logistic regression, we model the risk of CVD for the population stratified by ethnic group according to mover status, baseline deprivation and transitions between deprivation statuses. We show that the relationship between residential mobility and CVD varies between ethnic groups and is strongly influenced by the inter-relationship between residential mobility and deprivation mobility. Whilst residential mobility is an important determinant of CVD, much of the variation between ethnic groups is explained by contrasting deprivation experiences. To reduce inequalities in CVD within New Zealand, policies must focus on residentially mobile Māori, Pacific and South Asian populations who already have a heightened risk of CVD living in more deprived areas.