New research examining the effects of gaining Medicaid coverage on health outcomes shows mixed results. With a number of states opting to expand Medicaid under the Affordable Care Act, many have questioned whether the investment will ultimately pay off – for both patients and the state’s bottom line. Fortunately, new data from Oregon is available to answer some of those questions.

In 2008, Oregon chose to expand Medicaid, but had to limit enrollment because of budget constraints. As a result, the state set up a lottery system to select just 10,000 new enrollees from among 90,000 eligible residents. This allowed researchers to study health outcomes between those who won a slot vs. those who did not.

The study tracked thousands of people in both groups over two years, measuring important health indicators, including blood pressure and cholesterol, as well as whether patients were diagnosed with and receiving treatment for specific health conditions.

Researchers found no improvements in the diagnosis of hypertension and high cholesterol. However, for the Medicaid population there were marked improvements in diagnosis of diabetes and use of medication among those diagnosed. Further, those receiving care under Medicaid were less likely to be depressed and more likely to seek preventive care. They also spent less on “catastrophic out-of-pocket medical expenditures.”

While researchers concluded there were no significant differences in physical health outcomes, it’s hard to imagine a clinician that wouldn’t agree preventive care and early diagnosis lead to better health outcomes. Further, there’s something to be said for reducing the financial burden of those seeking catastrophic care. Even among the insured, those with paltry plans are more likely to delay care because of financial concerns, underscoring the importance of adequate coverage.

For Washington state, these latest results likely won’t change the state’s commitment to Medicaid, as lawmakers are already poised to take up the expansion. However, they might prompt policymakers to think more about the importance of comprehensive care as health reform moves forward. A top priority for policymakers will be how expanded access to health care can also lead to better health care and outcomes for everyone.

Coverage for more Washingtonians would surely be a positive change, but what will be especially important for patients is the quality and scope of care they receive. Coverage itself makes a difference for those that have gone without, but inadequate coverage only goes so far in improving long-term health outcomes.  Washington’s true measure of success in current healthcare reform efforts should lie in reducing rates of underinsurance, in addition to physical and mental health outcomes.