Medicaid experiment yields uneven clinical returns

Washington Expanding Medicaid to a randomly selected low-income population in one state improved people’s mental health and financial situations but had less of an impact on physical health outcomes, a study revealed.

In 2008, Oregon secured enough funding to expand Medicaid to 10,000 additional adults through a lottery selection process. Participants were ages 19 to 64 and below the federal poverty line but hadn’t otherwise been eligible for Medicaid. The experiment, known as the Oregon Health Study, provided insight into what might happen under the Affordable Care Act’s more sweeping Medicaid expansions in 2014, when states that opt to participate will extend eligibility up to an effective rate of 138% of the poverty level.

Researchers who evaluated the Oregon study and published results in the May 2 issue of {i}The New England Journal of Medicine{i} concluded that the Oregon expansion had mixed results on the clinical side (link).

Much of the results were in line with an earlier study conducted by many of the same researchers and published in the August 2012 {i}Quarterly Journal of Economics{i} (link). Both studies reported improvements in beneficiary access to care and self-reported health, as well as increases in care utilization and reductions in financial burdens for beneficiaries.

The newest study went somewhat further in its analysis, however. The earlier study was based on just one year’s worth of data, whereas the more recent findings analyzed two years of data that had been collected from 6,387 of the study’s participants and compared with more than 5,800 adults who had not been chosen in the lottery. Researchers in the second study also looked at detailed questionnaires collected during in-person interviews, as well as directly assessed physical outcomes such as hemoglobin A1c and blood pressure readings.

Expanded coverage reduced depression rates by 9 percentage points compared with the control group and increased self-reported mental health issues, according to the study. Getting on Medicaid also had its financial advantages: The study reported that it nearly eliminated catastrophic out-of-pocket expenditures for the Oregon population selected in the lottery. But the gains to their physical health weren’t as pronounced.

Covering these additional individuals under Medicaid didn’t seem to have much of an effect on reducing high cholesterol levels, for instance, or diagnosing conditions such as hypertension. Gains were made on detecting the probability of diabetes, yet the researchers “observed no significant effect on average glycated hemoglobin levels or on the percentage of participants with levels of 6.5% or higher,” according to the study.

Coverage may be long-term investment

Overall, the study “does not provide evidence that Medicaid coverage translates to measurable improvements in physical health in the first two years,” said Amy Finkelstein, PhD, the co-principal investigator and the Ford professor of economics at the Massachusetts Institute of Technology, in a statement.

Matt Salo, executive director of the National Assn. of Medicaid Directors, offered that the study’s time frame probably was too short to yield an effective sample of the project’s outcomes. Ways to tackle long-term chronic conditions such as diabetes and asthma “are not quick fixes. And from what I recall of the study, while the experiment was two years, the clinical data was only from 18 months or less. That’s really not enough time to get these issues sorted out,” Salo said.

What the study did show is that it was beneficial for low-income people to have Medicaid coverage, he said. The outcomes on mental health “prove why Medicaid is the largest and most effective funding source of mental health care in this country.” The reduction in financial burden for the lottery population also shouldn’t be discounted, Salo said.