Study: Medicaid expansion linked to decline in preventable hospitalizations

States that expanded Medicaid in 2014 and 2015 had reductions in hospital discharges, inpatient days and costs, a new study finds.

The study published Monday in Health Affairs suggests the potential for the Affordable Care Act’s (ACA's) Medicaid expansion to lower costs and reduce preventable hospitalizations.

Researchers estimated that the Medicaid expansion led to a 3.47% reduction in annual discharge rates for ambulatory care-sensitive conditions that range from diabetes and heart failure to infections or pneumonia. The estimated reductions in discharge rates were largely concentrated among respiratory and diabetes-related complications, the study added.

The expansion was also associated with a roughly 3% reduction in annual inpatient days for ambulatory care-sensitive conditions from 2014 to 2015.

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The Health Affairs study aims to build on existing evidence of greater health benefits from the Medicaid expansion.

“A recent systematic review of the literature on Medicaid expansions linked them to improvements in insurance coverage, access to preventive and primary care and chronic disease management,” the study said. “Building on this literature, our study found that Medicaid expansions were associated with meaningful downstream reductions in hospitalizations.”

But the study does come with several caveats. The study data didn’t allow researchers to examine individual-level changes in insurance coverage and behavior, and the post-expansion study period was relatively short.

The study was primarily based on state inpatient databases called the Healthcare Cost and Utilization Project. Researchers looked at inpatient discharge data from 36 states that participated in the project from 2009 to 2015.

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More research is also needed to explore differences between each individual state.

“Future research could explore the driving forces (such as provider capacity, participation, and reimbursement; and cultural and language barriers) behind the different effects of Medicaid expansions on preventable hospitalizations from state to state,” the study said.

So far, 37 states and the District of Columbia have adopted the Medicaid expansion under the ACA and 14 states have not, according to data from the Kaiser Family Foundation.

Three of those 37 states—Utah, Idaho and Nebraska—have not implemented the expansion yet.