Differences in the risk of cardiovascular disease for movers and stayers in New Zealand: a survival analysis
To explore if risk of cardiovascular disease (CVD) for participants who moved before their first CVD event is higher than for stayers, and examine whether the relationship is moderated by ethnicity.
The sample comprised 2,068,360 New Zealand residents enrolled in any Primary Health Organisation, aged between 30 and 84 years, had complete demographic information, and no prior history of CVD. Cox proportional regression was used to compare CVD risk between movers and stayers. The analysis was conducted for the whole sample and stratified by ethnicity.
The combined analysis suggested that movers have a lower risk of CVD than stayers. This is consistent for all ethnic groups with some variation according to experience of deprivation change following residential mobility.
Although mobile groups may have a higher risk of CVD than immobile groups overall, risk of CVD in the period following a residential mobility event is lower than for stayers. Results are indicative of a short-term healthy migrant effect comparable to that observed for international migrants.
KeywordsCardiovascular disease Residential mobility Deprivation Survival analysis New Zealand
Compliance with ethical standards
Ethical approval for this study was first granted by the Multi-Region Ethics Committee in 2011 (ref: MEC/11/EXP/078) with subsequent approvals from the Health and Disabilities Ethics Committee.
- Blakely T, Ajwani S, Robson B, Tobias M, Bonne M (2004) Decades of disparity: widening ethnic mortality gaps from 1980 to 1999. NZ Med J 117(1199):U995Google Scholar
- Grey C, Wells S, Riddell T et al (2010) A comparative analysis of cardiovascular disease risk profiles of five Pacific ethnic groups in New Zealand primary practice: PREDICT CVD-13. NZ Med J 123(1325):41–52Google Scholar
- Kerr AJ, McLachlan A, Furness S, Broad J, Riddell T, Jackson R, Wells S (2008) The burden of modifiable cardiovascular risk factors in the coronary care unit by age, ethnicity and socioeconomic status—PREDICT CVD-9. NZ Med J 121(1285):20–33Google Scholar
- Levesque LE, Hanley JA, Kezouh A, Suissa S (2008) Problem of immortal time bias in cohort studies: example using statins for prevention progression of diabetes. BMJ 340:908–911Google Scholar
- Ministry of Health (2004) Ethnicity data protocols for the health and disability sector. Ministry of Health, WellingtonGoogle Scholar
- Ministry of Health (2010) Tatau kahukura: Māori health chart book, 2nd edn. Ministry of Health, WellingtonGoogle Scholar
- Ministry of Health (2016) Enrolment in a primary health organisation. http://www.health.govt.nz/our-work/primary-health-care/about-primary-health-organisations/enrolment-primary-health-organisation. Accessed Nov 2016
- Riddell T, Jackson R, Wells S, Broad J, Bannink L (2007) Assessing Māori/non-Māori differences in cardiovascular disease risk and risk management in routine primary care practice using web-based clinical decision support: PREDICT CVD-2. NZ Med J 120(1250):U2445Google Scholar
- Salmond C, Crampton P, Atkinson J (2007) NZDep2006 index of deprivation. University of Otago, WellingtonGoogle Scholar
- Statistics NZ (2017) Data in the IDI. http://www.stats.govt.nz/browse_for_stats/snapshots-of-nz/integrated-data-infrastructure/idi-data.aspx. Accessed June 2017
- Warin B, Exeter DJ, Zhao J, Kenealy T, Wells S (2016) Geography matters: the prevalence of diabetes in the Auckland region by age, gender and ethnicity. NZ Med J 31(8.1):393Google Scholar
- Wells S, Riddell T, Kerr A et al (2015) Cohort profile: the PREDICT cardiovascular disease cohort in New Zealand Primary Care (PREDICT-CVD 19). Int J Epidemiol 46(1):22Google Scholar