Expanding Public Insurance to Rural Wisconsin Low-Income Childless Adults Increases the Use of Medical Care

Many states will expand Medicaid to 138 percent of the Federal Poverty Line as under  the Affordable Care Act.  However, there are, to date, only a limited number if studies evaluating the effects of public insurance programs on the use of health care of childless adults.  This study adds to this nascent literature. We use claims from a large integrated health system in rural Wisconsin and Medicaid enrollment files from January 2007 to September 2012 in order to measure the change in health case use after enrollment into a new public insurance program for low-income childless adults in Wisconsin. We employ individual level fixed effects models to examine outpatient, emergency department, and inpatient events for two years before and after insurance enrollment for 6,546 previously uninsured low-income adults.  We find that, in the two years following enrollment, service use increased substantially: outpatient visits by 35%, emergency department visits by 36%, and hospitalizations by 34%.  These findings suggest that public insurance expansions to childless adults have the potential to improve health but may lead to increased costs associated with increased utilization.