A new study finds that healthcare reform in Massachusetts led to a decline in the state’s death rate, suggesting that expanding coverage may make a positive impact on people’s lives nationwide.

One life was saved for every 830 people who gained insurance under 2006’s healthcare reform law in Massachusetts—the law that was a model for the Affordable Care Act (ACA).

This finding was reported in a new study conducted by the Harvard School of Public Health (HSPH). In the post-reform period, from 2007 through 2010, it is estimated that 320 lives were saved per year.

Benjamin Sommers, M.D., Ph.D., assistant professor of health policy and economics at the HSPH and lead study author, told Healthline, “This study is one part of a larger body of evidence that suggests that health insurance really can make a positive impact on people’s lives. That’s really important information to take into account when we evaluate the ACA or any other effort to expand coverage.”

For the study, published in the Annals of Internal Medicine, the researchers considered data from about 48 million people, including 4 million Massachusetts adults aged 20 to 64, as well as a control group of 44 million demographically similar adults in states that didn’t expanded health insurance coverage.

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In the years prior to the Massachusetts reform, from 2001 to 2005, the two groups had similar mortality rates. But in the post-reform years, from 2007 to 2010, the Bay State’s mortality rate dropped by 2.9 percent, while the death rate for the control group remained the same.

Even more significantly, deaths in Massachusetts from “healthcare amenable causes,” meaning conditions that can be greatly improved by having access to a doctor and medication, dropped by 4.5 percent. The study accounted for more than 100 ailments, including cancer, infections, heart disease, kidney disease, and diabetes.

“We were looking for conditions where you were more likely to benefit from healthcare,” said Sommers. “That’s where the mortality declines were really clear—with treatable conditions like cancer.”

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The healthcare reform law mandated that almost every Massachusetts resident have a minimum level of insurance coverage, provided free insurance for residents earning less than 150 percent of the federal poverty level, and required that employers with more than ten full-time employees provide coverage.

On an individual level, the new findings suggest that someone who gains health insurance is 30 percent less likely to die that year.

Emphasizing that uninsured people are also more likely to have lower incomes, less education, and be in worse general health, Sommers said, “These factors taken together make it difficult to know why there are differences in health and mortality for people who are uninsured. Is it because they don’t have insurance? Or is it all these other factors?”

To help answer that question, the study also looked at data from two national surveys, one conducted by the U.S. Census Bureau and the other by the U.S. Centers for Disease Control and Prevention. The findings suggest that healthcare reform had significant positive effects.

For example, compared with other New England states, after the 2006 health law, Massachusetts saw a 57 percent drop in the rate of uninsured people. The state also had a 22 percent reduction in people delaying healthcare due to cost and a 13 percent decline in people reporting they have no “usual source of care,” such as a family doctor. There was also a 5 percent drop in people reporting their health got worse in the past year.

Looking at all of these changes, Sommers explained, “You start to see that coverage led to better access to services and more preventive care. People felt better, and then ultimately the last step in the pathway is that death rates went down, as well.”

The researchers also found that the greatest health gains were in lower-income counties which had a higher percentage of uninsured adults before the health reform.

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Sommers cautioned about generalizing from any single state and any single policy. Acknowledging that the ACA and the Massachusetts healthcare law are fairly similar, Sommers said, “They both generally have the goal of expanding health insurance coverage to people who didn’t have coverage. But there are also a lot of differences between Massachusetts and the rest of the country that may impact whether the law is more or less successful in other areas.”

For example, prior to health reform, Massachusetts had a higher median income, less poverty, and a lower rate of uninsured people than the U.S. as a whole. Massachusetts also has more doctors per person than any other state, and the health law was passed with bipartisan support. In contrast, the ACA has faced massive political opposition.

Sommers noted that some of these factors could suggest that the ACA might have an even bigger effect nationally than the Massachusetts reform—while others might lead to the opposite conclusion. “The fact that Massachusetts, even before the law, had … a healthier population to begin with, you might think that the ACA will have an even bigger impact in places where there’s more poverty, more uninsured people, and worse health at baseline.”

On the other hand, the reverse could prove to be true: “Massachusetts was particularly well-suited to expanding coverage because it already had a very healthy medical system with a lot of healthcare providers,” he said. “And it was being implemented in an environment that was very cooperative and supportive of making the law work, which is not the case everywhere.”