Disruption and selection: the income gradient in mortality among natives and migrants in Sweden

BACKGROUND: The income gradient in mortality is generated through an interplay between socio-economic processes and health over the life course. International migration entails the displacement of an individual from one context to another and may disrupt these processes. Furthermore, migrants are a selected group that may adopt distinct strategies and face discrimination in the labour market. These factors may have implications for the income gradient in mortality. We investigate whether the income gradient in mortality differs by migrant status and by individual-level factors surrounding the migration event. METHODS: We use administrative register data comprising the total resident population in Sweden aged between 30 and 79 in 2015 (n = 5.7 million) and follow them for mortality during 2015–17. We estimate the income gradient in mortality by migrant status, region of origin, age at migration and country of education using locally estimated scatterplot smoothing and Poisson regression. RESULTS: The income gradient in mortality is less steep among migrants compared with natives. This pattern is driven by lower mortality among migrants at lower levels of income. The gradient is less steep among distant migrants than among close migrants, migrants that arrived as adults compared with children and migrants that received their education in Sweden as opposed to abroad. CONCLUSIONS: Our results are consistent with the notion that income inequalities in mortality are generated through life-course processes that may be disrupted by migration. Data restrictions prevent us from disentangling life-course disruption from selection into migration, discrimination and labour market strategies.