Enrolling eligible, low-income Californians—including the 1.7 million uninsured projected to be eligible for Medi-Cal—is the focus of Affordable Care Act implementation right now. But in the longer term, there is a bigger question: How will the expansion of Medi-Cal under the Affordable Care Act impact the medical care and health of those who gain coverage?
It may come as a surprise, but the effect of insurance on health care use and outcomes is not well understood. The best recent evidence we have comes from the Oregon Health Insurance Experiment, a collaborative effort among academic researchers and state health department officials to evaluate how access to public insurance affects the health of low-income residents.
Early results from this rigorous study, which began in 2008, indicate that people who gain Medicaid coverage use more health care services—both inpatient and outpatient. The study found improvements in primary care access and significant increases in the use of preventive care such as mammograms and cholesterol screening. Medicaid coverage also reduced observed rates of depression and greatly reduced financial hardships and medical debt. But these positive results were not accompanied by signs of improved physical health outcomes, such as changes in blood pressure or cholesterol levels, and the study found evidence of increased use of emergency rooms among those who gained Medicaid coverage.
Of course, these results are from a short period of time: the first one to two years of coverage. If people are able to maintain coverage and consistent contact with providers, we could see improvements in health outcomes and decreased use of high-cost care settings such as ERs over time.
The good news is that these improvements may have gotten a head start in California.Before this year’s Medi-Cal expansion under the Affordable Care Act, the state expanded access to more services and better coordinated care through county-based programs under a federal waiver designed to prepare California for health care reform. This means that more than 600,000 uninsured residents, who will comprise a large share of new Medi-Cal enrollees this year, were brought into systems of care and already had the opportunity to receive needed services. This could mean that utilization in California will not increase as much as it did in the Oregon experiment. Evaluations of these county-based programs suggest that hospitalizations and ER visits could be reduced, but this will probably take longer than one or two years.
So while there is promising evidence of the benefits expanded Medicaid coverage can offer, including financial protection and increased use of preventive and primary care, it will probably take some time to bring about other desired changes.