Giving more people health insurance could save tens of thousands of lives nationwide, according to a new analysis of data from Massachusetts, whose reforms became the model for President Obama's health law.
Throughout the national debate over the Affordable Care Act, critics have questioned whether expanding coverage results in better health. The new analysis adds to the growing evidence that it does.
Mortality rates in Massachusetts measurably improved compared with similar places around the country after the state began guaranteeing its residents health coverage in 2006, according to researchers at the Harvard School of Public Health, Brigham and Women's Hospital and the Urban Institute.
The study, published Monday in the Annals of Internal Medicine, also implicitly warns that gaps among states in the health of their populations may widen in coming years. That divide will result from some states taking advantage of federal money to provide health coverage and others opting out of the system.
About half the states — including most of those with the least healthy populations — have decided not to expand their Medicaid programs under the law.
The study's lead author, Dr. Benjamin D. Sommers, cautioned against assuming national trends from one state's data. But the look at Massachusetts suggests the reforms are responsible for improving health.
"There is a change happening in Massachusetts that is not happening elsewhere," Sommers said.
Sommers, a researcher at Harvard, has been a part-time advisor to the U.S. Department of Health and Human Services, but the research was conducted independently.
Eight years ago, Massachusetts became the first state in the nation to create a system of universal coverage, guaranteeing its poorest residents Medicaid and providing subsidies to help moderate-income residents get insurance on a state marketplace where insurers could not turn away the sick.
That structure became the foundation for the Affordable Care Act, which Obama signed in 2010.
Previous research has shown this system increased access to care and reduced Massachusetts' uninsured rate, now at less than 5%, the lowest in the nation.
A similar trend is emerging nationally, as surveys indicate millions have gained coverage since state marketplaces created by the federal law opened in October. A nationwide Gallup poll released Monday showed the percentage of working-age adults without coverage dropped from 18% last fall to 13.4% in April.
But the law's critics continue to question the effect the expansion will have on Americans' health.
Many point to research conducted on Oregon's expansion of Medicaid in 2008. That study found people who gained coverage made little progress controlling their cholesterol and blood pressure compared with low-income Oregonians without Medicaid. The researchers scrutinizing Massachusetts' experience looked at a longer-term — and arguably more consequential — measure of health: mortality.
That is important, said Katherine Baicker, a health economist at Harvard and former Bush administration official who has been studying Oregon and co-wrote the Massachusetts study. "Studies like this one can take advantage of both longer time frames and larger sample sizes," she said.
Unlike in Oregon, the researchers did not have a natural control group of state residents who did not get health coverage. To establish a control group, they compared Massachusetts with 513 counties around the country with similar demographics, poverty rates and rates of health coverage.
They analyzed what happened to mortality rates in Massachusetts and the control group in the five years before and after the state enacted its reform.
Overall, mortality rates declined 2.9% in Massachusetts after the reform compared with the control group. That suggests one death was prevented for every 830 people who gained coverage, according to the study.
"These are really important findings," said Sara Collins, vice president at the Commonwealth Fund, a nonpartisan research foundation that studies healthcare systems. "We already know people with health insurance have a very different quality of life.... This study provides convincing evidence that increasing the number of people with insurance leads to lower rates of mortality."
The Massachusetts researchers found the reduction was even more pronounced in deaths from diseases that are considered treatable with good access to medical care. So-called healthcare-amenable mortality fell 4.5% in Massachusetts compared with the control group.
Researchers also found reductions in mortality were most pronounced in Massachusetts counties with lower incomes and lower insurance coverage before reform, another indication that the insurance expansion probably had an effect.
The researchers saw no evidence of a decline in mortality among elderly residents, who, like their counterparts nationwide, already had guaranteed coverage through the federal Medicare program.
The authors cautioned that the health gains in Massachusetts could possibly be explained by some other factors that they couldn't identify.
And they warned that many other states do not have Massachusetts' healthcare advantages. In addition to having broader insurance coverage, the state has a large supply of primary care physicians, a record of tracking quality and a civic tradition of working to improve health.
The authors nonetheless concluded the prospects for improvements in health nationwide are good: "While this analysis cannot demonstrate causality, the results offer suggestive evidence that the Affordable Care Act — modeled after the Massachusetts law — may impact not only coverage and access but also mortality."Copyright © 2015, Los Angeles Times