Into the maelstrom of debate over whether Medicaid should cover more people comes a new study by Harvard researchers who found that when states expanded their Medicaid programs and gave more poor people health insurance, fewer people died.
The study, published online Wednesday in the New England Journal of Medicine, comes as states are deciding whether to expand Medicaid by 2014 under the Affordable Care Act, the Obama administration's health care law.
Attempts to research the issue have encountered the vexing problem of how to compare people who sign up for Medicaid with those who are eligible but remain uninsured. People who choose to enroll may be sicker, or they may be healthier and simply more motivated to see doctors. The new study reflects an effort to get around that problem and allow policymakers to make "evidence-based decisions," said Katherine Baicker, an investigator on the study who served on former President George W. Bush's Council of Economic Advisers.
The study analyzed data from three states that had expanded their programs in the past decade to cover a population not normally eligible for Medicaid: low-income adults without children or disabilities. The new law also expands coverage to a similar population nationally.
Researchers from Harvard's School of Public Health looked at mortality rates in those states -- Arizona, Maine and New York -- five years before and after the Medicaid expansions, and compared them with those in four neighboring states -- Nevada, New Mexico, New Hampshire and Pennsylvania -- that did not put such expansions in place.
The number of deaths for people age 20 to 64 -- adults too young to be considered elderly -- decreased in the three states with expanded coverage by about 1,500 combined per year, after adjusting for population growth in the states, said Dr. Benjamin Sommers, a physician and an assistant professor of health policy and economics who was a study author.
In the five years before the expansion, there were about 46,400 deaths per year, while in the five years after, there were about 44,900 deaths per year. During the same period, death rates in the four comparison states increased, said Sommers, who began a yearlong stint as an adviser to the Department of Health and Human Services after the research was completed, but before it was published.
'Everything we could'
When researchers adjusted the data for economic factors such as income and unemployment rates, and population characteristics such as age, sex and race, and then compared those numbers with neighboring states, they estimated that the Medicaid expansions were associated with a decline of 6.1 percent in deaths. That is about 2,840 per year for every 500,000 adults added.
"I can't tell you for sure that this is a cause-and-effect relationship," that the Medicaid expansion caused fewer non-elderly adults to die, Sommers said. "I can tell you we did everything we could to rule out alternative explanations."