Improved mental health seen with Medicaid coverage expansion

Medicaid coverage was linked to “substantially reduced” depression and the increased diagnosis of diabetes and the use of diabetes medication among low-income adults, according to a new study.

At the same time, Medicaid coverage had no detectable effect on the prevalence of diabetes, high cholesterol, or high blood pressure, according to the study published in the May 2 issue of The New England Journal of Medicine.

“Medicaid coverage generated no significant improvements in measured physical health outcomes in the first two years, but it did increase the use of healthcare services, raise rates of diabetes detection and management, lower rates of depression, and reduce financial strain,” the researchers wrote.

The study was led by Katherine Baicker, PhD, professor of health economics at Harvard School of Public Health and Amy Finkelstein, PhD, Ford professor of economics at MIT. As part of the ongoing Oregon Health Insurance Experiment, the researchers are using a randomized, controlled study design to evaluate the impact of covering the uninsured with Medicaid.

After Oregon held a lottery in 2008 to give additional low-income, uninsured residents access to its Medicaid program, the researchers conducted more than 12,000 health exams and interviews with lottery participants.

They found that Medicaid increased the probability of being diagnosed with diabetes after the lottery by 3.8 percentage points, compared to the 1.1% in the control group. Medicaid coverage increased the use of diabetes medication by 5.4 percentage points, compared to 6.4% of the control group who use diabetes medication.

Medicaid reduced rates of depression by 9 percentage points, compared to the 30% of the control group screening positive for depression. The researchers also noted increased self-reported mental health with Medicaid coverage.

In addition, Medicaid virtually eliminated out-of-pocket catastrophic medical expenditures and reduced other measures of financial strain.

“The study highlights the important financial protections that Medicaid provides, as well as the substantial improvements in mental health, but does not provide evidence that Medicaid coverage translates to measurable improvements in physical health in the first two years,” Finkelstein said.

For additional information about this ongoing research program, go to www.nber.org/oregon.