Duration of residence and disease occurrence among refugees and family reunited immigrants: test of the ‘healthy migrant effect’ hypothesis

Abstract

Abstractobjectives The 'healthy migrant effect' (HME) hypothesis postulates that health selection has a positive effect on migrants' health outcomes, especially in the first years after migration. We examined the potential role of the HME by assessing the association between residence duration and disease occurrence.methods We performed a historical prospective cohort study. We included migrants who obtained residence permits in Denmark between 1 January 1993 and 31 December 2010 (n = 114 331). Occurrence of severe conditions was identified through linkage to the Danish National Patient Register. Hazard Ratios (HRs) were modelled for disease incidence by residence duration since arrival (0-5 years; 0-10 years; 0-18 years) adjusting for age and sex.results Compared with Danish-born individuals, refugees and family reunited immigrants had lower HRs of stroke and breast cancer within 5 years after arrival; however, HRs increased at longer follow-up. For example, HRs of stroke among refugees increased from 0.77 (95% CI: 0.66; 0.91) to 0.96 (95% CI: 0.88; 1.05). For ischaemic heart disease (IHD) and diabetes, refugees and family reunited migrants had higher HRs within 5 years after arrival, and most HRs had increased by end of follow-up. For example, HRs of IHD among family reunited migrants increased from 1.29 (95% CI: 1.17; 1.42) to 1.43 (95% CI: 1.39; 1.52). In contrast, HRs for TB and HIV/AIDS showed a consistent decrease over time.conclusion Our analyses of the effect of duration of residence on disease occurrence among migrants imply that, when explaining migrants' advantageous health outcomes, the ruling theory of the HME should be used with caution, and other explanatory models should be included.

The Risk of Ischemic Heart Disease and Stroke Among Immigrant Populations: A Systematic Review

“…Immigrant cohorts with a longer duration of residence in their new country were at an increased risk of IHD and stroke in most studies. 27,30,33 However, in intergenerational studies, risk levels appeared to converge to that of the host population, as has been shown in previous studies. 48 This observation might be explained by immigrants' adoption of the lifestyles of their host country increasing with greater duration of residence regardless of their risk at the time of arrival.…”

“…27,30,32,33 In England and Wales, duration of residence was associated with an increased risk of stroke mortality among Caribbean immigrants (hazard ratio, 1.38 per year of residence; 95% CI, 1.10-1.74), 32,33 and in South Asian immigrants, stratified according to age, a trend toward increased IHD mortality risk with each year of residence was observed in all age groups; however, this was not statistically significant. 32 In Denmark, IHD risk among family members reunited with other immigrants appeared to increase with duration of residence; however, the risk of stroke appeared unchanged.…”

“…All studies stratified immigrants according to country or region of birth, except 2 from Canada, in which new immigrants were compared with long-term residents comprised of Canadianand foreign-born, and 1 from Denmark. 30,34,35 …”

“…32 In Denmark, IHD risk among family members reunited with other immigrants appeared to increase with duration of residence; however, the risk of stroke appeared unchanged. 30 In Sweden, no evidence of a clear pattern of changing relative risk of AMI among immigrant subgroups compared with the Swedish-born population over 20 years of residence was found, although the risk among some groups appeared to converge to levels of the Swedish population. 27 …”

Long-term effects of neighbourhood deprivation on diabetes risk: quasi-experimental evidence from a refugee dispersal policy in Sweden

“…6, 17, 18 Moreover, incidence may be higher among refugees than among immigrants more generally. 19 In recent years, the European Union has experienced the largest inflow of immigrants and refugees since the end of the Second World War. The current wave of immigration includes a majority of individuals from the Middle East and North Africa, where T2D prevalence is the highest of any region worldwide: 11% among adults aged 20–79 in 2013.…”