Could immigration reform improve our health?

During his State of the Union address last month, President Obama challenged the assembled lawmakers to tackle comprehensive immigration reform. The issue has proven a divisive one in our national political discourse, and most of the discussion focuses on the political ramifications. Pundits have discussed how immigration reform might impact the Latino vote, as well as what types of immigrants would be eligible for citizenship, and what the role of border security is, to name a few hotly-contested questions in the current debate. Amid this political maelstrom, few have considered how comprehensive immigration reform might affect the nation's health. Understanding the health implications of immigration reform may contribute to the public discourse on the topic, and may also provide insights that are relevant to the equally divisive health reform debate. Remember that undocumented immigrants are explicitly excluded from Obamacare.

To examine this question carefully, I'll first discuss what we know about the demographics of undocumented immigrants in the United States. Then I will review the available evidence describing the health of this population and their health care use. First, however, I would like to acknowledge the challenges to studying this vulnerable population and the potential inaccuracies of the resulting data. It is widely known that Census reports include small numbers of undocumented immigrants. It is just as hard to assess the health status of this population as it is to count their numbers. Undocumented immigrants are also under-represented in most large health surveys, with a few exceptions presented below. As a result, our knowledge about the health of undocumented immigrants and their use of the health-care system is limited.

According to the best available evidence, there are 11.1 million undocumented immigrants residing in the U.S. — more than one-quarter of the nation's total immigrant population. It is estimated that there are 550,000 undocumented immigrants living in New Jersey, the fifth-largest of any state, and 160,000 in Pennsylvania, many of whom work in restaurants and have fueled the recent food renaissance in Philadelphia. At the national level, most undocumented immigrants are Latinos — 82 percent, to be exact. Because Latinos constitute the overwhelming majority of the nation's undocumented immigrants, let's focus on Latinos when reviewing the medical literature and discussing the impact of immigration reform on the nation's overall health.

Studies have consistently demonstrated that undocumented Latino immigrants use less health care than U.S. citizens who are either Latino or white. One survey study based in California and Texas — traditional centers for Latino immigration and Nos. 1 and 2 in the state rankings — reported that undocumented Latino immigrants were less likely to see a doctor than a national sample of Latino U.S. citizens. The same study showed that undocumented Latinos who saw a physician had approximately half the number of doctor visits as Latino citizens. A recent study using a large sample representative of California's population compared the health care use of undocumented Latinos to that of U.S.-born Latinos and whites. This study found that 87% percent of U.S.-born whites had visited a physician in the previous year, compared to 83% of U.S.-born Latinos and just 64% of undocumented Mexican immigrants. Emergency room visits were also less common among undocumented Latino immigrants than among Latino or white citizens. Although low health care utilization among undocumented immigrants may be related to access barriers or fear of deportation, the final study reported the same principal finding after controlling for socioeconomic factors, insurance, and need.

The National Health and Nutrition Examination Survey (NHANES), which is representative of the entire U.S. population, can help us examine the health status of the nation's Latinos. This publicly-available dataset allows us, for example, to compare the health of Latino citizens and non-citizens. (Note: The non-citizen group encompasses both undocumented immigrants and documented immigrants without full citizenship status. So the analysis that follows is a conservative estimate of differences between Latinos who are citizens and those who are undocumented.) I chose to examine two common and burdensome health conditions — obesity and diabetes — which together account for over $350 billion of annual health care spending. Compared to Latinos who are not U.S. citizens, Latino citizens were 33% more likely to be obese, 245% more likely to be morbidly obese, and 150% more likely to have diabetes. These nationally-representative data reveal a very clear picture: Latinos who are not U.S. citizens are much healthier than Latino citizens, at least with respect to obesity and diabetes. The same pattern of increased obesity and diabetes burden was consistent when including U.S. citizens of all races and ethnicities in the analysis compared to all non-citizens.

How, then, might comprehensive immigration reform impact the nation's health? The data presented above — in addition to other studies not reviewed here — suggest that undocumented immigrants are healthier and use fewer health care services than U.S. citizens. As mentioned above, however, the evidence on these points is limited by the inherent difficulty in counting and studying this population. If the data on diabetes and obesity are indicative of the overall health status of undocumented immigrants, this picture would illustrate a potential missed opportunity to include current undocumented immigrants in the Affordable Care Act. This population did not make the cut in Obamacare for obvious political reasons. But speaking only from the perspective of our nation's health: including 11.1 million individuals who may be healthier and use less health care than the rest of us would have helped lower insurance premiums in the new health exchanges,and perhaps would have cost less to cover via Medicaid expansion than will those who will be included.

In addition, if current undocumented immigrants became citizens and joined our national discourse on health, perhaps the rest of us could learn more from this population, and examine more closely what makes this group healthier. Such a dialogue might help those new citizens preserve the attitudes, values, and behaviors that promote their health.

If we can put the demagoguery aside, it seems the American health care system could actually benefit from including this population. Still, there is a central question that remains unanswered: As immigrants gain citizenship and become "more American," why does their health status deteriorate? A large body of evidence shows that Latinos' health worsens the longer they live in the United States. If we can figure out why, these same factors that keep many undocumented immigrants healthy might also help longtime citizens improve their own health. After all the time wasted attacking undocumented workers, wouldn't that be ironic?

Matt O'Brien is an assistant professor of medicine and public health at Temple University and a founder of Puentes de Salud, a health center serving immigrant Latinos in South Philadelphia.

Read more about The Public's Health.