An important component of the Affordable Care Act is that it facilitated states expanding their Medicaid programs, offering health insurance to low-income, childless adults. Experts hoped that these expansions would not only improve the general health of this vulnerable population, but also save taxpayer dollars by increasing preventive care and decreasing risky health behaviors such as smoking.

“Preventive care is seen as a way to improve health and also save the health care system money,” said John Cawley, professor of policy analysis and management and of economics, and co-director of the Cornell Institute on Health Economics, Health Behaviors and Disparities. “There’s often a tradeoff between those two priorities – you can make people healthier by providing costly treatments, or you can save the health care system money by reducing care. In contrast, preventive care has the potential, if it’s properly targeted, to save the health care system money in the long run by reducing disease and improving health.”

In a newly published study, Cawley and co-authors Kosali Simon and Aparna Soni of Indiana University demonstrate for the first time that the state-level expansions of Medicaid that were promoted by the Affordable Care Act succeeded in improving preventive care among low-income Americans. Specifically, low-income childless adults received 5.4 percent more preventive services in the past year, and the probability that they had a dental visit in the past year rose 8.7 percent.

However, Cawley and colleagues did not find any evidence that the Medicaid expansions led low-income adults to reduce their unhealthy habits – there was no detectable change in smoking, alcohol abuse, exercise or obesity.

In addition to the increased preventive care, the study finds numerous other benefits associated with the Medicaid expansions among low-income childless adults, including a 16.6 percent increase in the probability of health insurance coverage, a 6.6 percent increase in the probability of having a personal doctor, an 11.5 percent reduction in the probability that cost was a barrier to health care, a 4.6 percent improvement in self-assessed health and a 10.4 percent reduction in the number of unhealthy days.

The study, “The Impact of Health Insurance on Preventive Care and Health Behaviors: Evidence From the First Two Years of the ACA Medicaid Expansions,” was published online Jan. 16 in the Journal of Policy Analysis and Management.

One of the more controversial features of the Affordable Care Act (or “Obamacare”) was state-level expansions of Medicaid. When the dust settled after much litigation in 2012, states had the right to opt in or out of the expansions, which were especially geared toward increasing coverage for low-income, childless adults.

Thirty states plus the District of Columbia had adopted the expansion by the end of 2015; 20 states had not. So Cawley and colleagues accessed the Behavioral Risk Factor Surveillance System, a nationwide telephone survey coordinated by the Centers for Disease Control and Prevention, and extracted data on nearly 70,000 low-income childless Americans. They then compared the change in outcomes for those living in states that expanded Medicaid to the change in outcomes for those living in states that did not.

“The expansions have had numerous benefits,” Cawley said. “They provide low-income individuals with health insurance coverage and access to care. They are also increasing some forms of preventive care, such as dental visits. We do not, however, see increases in other forms of preventive care like cancer screenings. And, we don’t see any evidence of reductions in smoking, alcohol abuse, or obesity, although we do find overall benefits in terms of self-assessed health and fewer sick days.”

Cawley and colleagues also found no evidence that low-income people engage more in risky behaviors once they gain health insurance coverage, a phenomenon known as moral hazard. “One might be concerned that, if people know that if they get sick that most of their costs will be covered by insurance, they would take less care of themselves or take more risks,” Cawley said. “We don’t find any evidence of that kind of moral hazard with respect to smoking, heavy drinking or lack of exercise.”

The findings may have far-reaching implications for Americans who gained coverage under various facets of Obamacare, which could soon be repealed. “If the entire ACA literally disappeared and there was no replacement, we’d see millions of people lose health insurance,” Cawley said. “We’d see decreases in preventive care. Down the road, that would mean more people would be sick, and the health care system would be more burdened.”

This article is written by Joshua A. Krisch and was published in the Cornell Chronicle on February 1, 2017.