Throughout his political career, President Trump has defined himself in large part by his antipathy towards immigrants, from his disparaging remarks about Mexican immigrants at the start of his presidential campaign, to his administration’s ban on immigrants from several majority-Muslim countries, to his more recent obscene characterization of Haiti and African countries. Even in this context, however, his administration’s decision to separate from their parents the children of immigrants arriving at the country’s border stands out as an especially cruel, mean-spirited act. As Ali Noorani (SPH’99), executive director of the National Immigration Forum, has said, “Separating parents and children in an attempt to deter people who are fleeing violence from legally seeking asylum is cruel to families, harmful to children, and wholly contrary to American values.”
This policy is also harmful to health. Migrants face a range of health challenges, both during their journey and during their life in the country in which they settle. To add the trauma of forced family separation to what is already a difficult and sometimes dangerous experience helps no one and potentially harms many. With this in mind, we today rerun a modified version of a Dean’s Note on migration and health through the lifecourse, in the hope that it will inspire reflection on the challenges faced by immigrants and our collective responsibility to care for their health.
In 2013, there were 232 million immigrants living worldwide, and about 2.4 million migrate across national borders each year. It is estimated that 763 million people live within their country of birth but in a different region, having migrated within national borders. Economic, political, and social forces drive migration. Migrants who are forced to leave their country due to war or persecution are typically called refugees. There were 19.5 million refugees worldwide at the end of 2014. I discuss here the broader process of migration and health, drawing attention to an important determinant of health, and linking back to lifecourse perspectives and urban health frameworks that might help explicate how migration affects health.
It is not at all clear whether the health of migrants is better or worse than that of counterparts who do not migrate, or in receiving countries. Some studies, such as one comparing cardiovascular risk factors among Portuguese who stayed in Portugal to those who migrated to Switzerland, find very few differences in health between migrants and those who do not leave their countries of origin. Others have documented worse outcomes among migrants; one paper looking at the country of origin among people living in Italyfound that citizens of countries with high migration pressure had a higher prevalence of diabetes, mostly among immigrants from Southern Asia and Northern Africa, and especially among females. This study also found that immigrants from these areas were less likely to be tested for glucose levels. One review that looked at a few different countries in Europe determined that immigrant effects vary across Europe. Independent of country of origin, this review found that immigrants fared worse overall than natives in France, Belgium, and Spain but better than natives in Italy, contrary to the previously mentioned study. Complicating matters, in the United States, low-income immigrants from Mexico and Southeast Asia have consistently shown better birth and death outcomes than their native American counterparts; this has been referred to as an “epidemiological paradox,” informed by the unexpected observation of better health among groups with lower socioeconomic status. This effect has been explained through the healthy migrant effect, or the idea that people who choose to or who are able to leave their place of birth are likely to have better health than those who do not or cannot; this is compounded by a “selection return migration” wherein sicker people return to their origins. This effect has been both documented and challenged in the United States.
In light of conflicting evidence, a lifecourse perspective suggests a useful approach to understanding migration and health may involve a consideration of migration processes as they intersect with life experiences, including pre-migration, peri-migration, and post-migration circumstances. Starting from the former, a review of immigrant and refugee youth in Canada highlighted the importance of pre-migration experiences, including trauma and post-migration family and school environments. Multiple characteristics of the pre-migration experience, captured by migrant country of origin, have been shown to determine heterogeneity in immigrant health. Although the literature is sparser, there is ready evidence of the link between the migration experience itself and health, particularly for vulnerable populations. As for post-migration experiences, the conditions experienced by migrants in their new countries appear, not surprisingly, to be strongly determinative of migrants’ health. A study in Denmark found that refugees were disadvantaged in terms of some cardiovascular disease outcomes and equal or better off than Danish-born in others, but family-reunified immigrants had significantly lower incidence of stroke, cardiovascular disease, and myocardial infarction across the board. Conditions of assimilation more broadly are associated with health. Legal status in the host country is associated with access to a broad range of health services and resultant better health. Various studies have shown that residence in “ethnic enclaves” after immigration is associated with better health outcomes over time and can help mitigate unhealthy assimilation. Extending the lifecourse paradigm across generations, a study on rural-to-urban migrants in Bangladesh found that under-5 mortality was almost twice as highamong children born to urban migrants compared with children born to lifelong urban natives, likely due to a disadvantaged economic status.
A lifecourse perspective also suggests that the intersection of the migration experience with life stages may illuminate the dynamics that shape health among migrants. A study of immigrants to the US based on the National Comorbidity Study Replication found lower risk of psychiatric disorder among immigrants, with higher risk associated with earlier age of immigration and longer duration of residence. This could imply that any protective effect associated with immigration is attenuated when immigrants experience a longer period of socialization in the US. A similar effect was found in Shenzhen, China, where migration before adulthood was a predictor of major depressive disorder. We have also seen a change in obesity over time, where newly arrived immigrants to the US from several different countries had a significantly lower prevalence of obesity compared to US-born residents but saw that prevalence dramatically increase as more years passed since immigration.
Much of the literature on intra-national migration has focused on rural-to-urban migration within one’s own country. A growing literature has studied this in China, informed by the country’s rapid urbanization since the turn of the century. Rural-to-urban migrants in China generally have more communicable diseases as well as worse maternal and infant health. The migrant population in China tends to be younger, male, and single, which may confound relationships between migration and health; further complicating the issue is that migrants are often excluded from urban health services and insurance. One study in Beijing found that perceived social inequity and experience of discrimination were associated with mental health problems among rural migrants.
Some populations migrate more than once in a lifetime or temporarily migrate, including relocating for occupational purposes, but remain linked to a rural household. Several authors have compared migrants to rural residents who do not leave instead of to urban-born residents. Eric Nauman and colleagues used a longitudinal approach to follow migrants from rural western Thailand to urban destinations such as Bangkok and then assessed the migrants, return migrants, and rural counterparts who remained in origin villages. Their findings supported the “healthy migrant” hypothesis: Migrants were physically healthier than non-migrants both before and after moving. Migrants who stayed in urban destinations showed an improvement in mental health status, and return migrants fared worse on both physical and mental health indicators. The World Health Organization Study on Global AGEing and Adult Health (SAGE) compared behavioral risk factors for non-communicable diseases across rural, urban, and migrant populations in several different countries, finding that, with some exceptions based on destination, alcohol consumption and occupational physical activity were lower in migrant and urban groups.
The particularities of the migrant experience over the lifecourse, the life stage at migration, and the particular macrocontext, urban or not, all contribute to the health of migrant populations, suggesting the utility of these framing perspectives to help organize our thinking and research questions, aimed at understanding how migration processes shape health.
I hope everyone has a terrific week. Until next week.