Professor Bernard Black and Feinberg Professor Abel Kho Receive $2.25 Million Grant to Study Effect of Medicaid Expansion on Diabetes

December 08, 2015

The expansion of Medicaid under the Patient Protection and Affordable Care Act of 2010 (ACA) is a cornerstone of the ACA effort to reduce the number of uninsured. But what affect will it actually have on the diagnosis, treatment, and outcomes of chronic disease?

That’s the question Bernard Black, Nicholas D. Chabraja Professor at Northwestern Pritzker School of Law, and Feinberg School of Medicine Professor Abel N. Kho, director of the Institute for Public Health and Medicine’s Center for Health Information Partnerships, are teaming up to answer with a $2.25 million grant from the Centers for Disease Control and the National Institute for Diabetes and Digestive and Kidney Diseases.

The five-year study, “The Effect of ACA Medicaid Expansion on Diabetes: Diagnosis, Treatment, and Health Outcomes,” will assess how Medicaid expansion affects near- and medium-term diabetes diagnosis, treatment, compliance, and health outcomes, and the economic effects of Medicaid expansion for diabetic patients.

That some states chose to expand Medicaid, and others did not, provides an excellent opportunity for a natural experiment, Black explained.  “By comparing diagnosis, treatment, evidence of patient compliance, and health outcomes for new Medicaid enrollees in ‘expansion states’ to outcomes for similar persons in non-expansion, or  ‘control’ states, we will find out, with good precision, what happens when you give people Medicaid,” Black said.

Black and Kho believe diabetes is an important disease to study using this method, since early diagnosis and patience adherence to treatment are particularly important to prevent longer-term complications and mortality. They also believe their research design can be used to study the effect of Medicaid expansion on other ailments as well.

They will use data from two major electronic health record networks, which will give them access to a sample of 9 million patients in nine states—five expansion and four control. The large sample will help them evaluate the effects of various factors on outcomes, including state- specific Medicaid policies, income, gender, and ethnicity.

Black says that previous research has suggested that Medicaid coverage leads to increased diabetes diagnoses and prescription of diabetes medications, but not to a significant decrease in blood sugar levels—a key indicator of improved health for diabetes patients.  But no previous study has matched the sample size, study length, and richness of data as will Black and Kho’s. 

In addition to providing answers to questions about diabetes care specifically, the research will provide useful information for assessing the health and financial effects of Medicaid expansion—which has broad policy implications. Additionally, Black and Kho believe their study will highlight the exciting research potential of electronic health record data.