Association for Public Policy Analysis & Management

Study Design:  We employ individual level fixed effects poisson models and regression discontinuity to examine medical care visits for two years before and after insurance enrollment for two samples of previously uninsured low-income adults that differ according to participation in safety net programs. We also determine whether the impacts of public health insurance on the use of care differ for men and women. Data come from claims from a large integrated health system in rural Wisconsin and Medicaid enrollment files between January 2007 and September 2012.

Population Studied: This study examines uninsured low-income adults who reside in a multi-county area in predominantly rural central and northern Wisconsin. The two samples studied differed according to whether they participated in safety net programs prior to enrollment in public insurance coverage.

Principal Findings:  Among both safety net patients and non-safety net patients, public insurance enrollment led to substantial increases in preventive care visits, although outpatient visits fell overall among safety net patients while they increased among non-safety net patients. No change in emergency department visits was observed, though for both groups inpatient hospitalizations increased.

Conclusions: This study was motivated in part by the expectation that the ACA Medicaid expansions for childless adults are likely to have differential effects on care use. Our results provide insight into one source of variation: participation in safety net services prior to enrollment. The breadth of a given area’s safety net system, and prior safety net utilization among the newly enrolled in the area, could affect utilization of outpatient services in particular.

Implications for Health Policy: The results of this analysis suggest that public insurance expansions to childless adults have the potential to increase access to and use of health care services and, by extension, the potential to improve health. The large increase in Medicaid coverage and reduction in rates of uninsurance resulting from the Affordable Care Act highlight the significance of these findings for stakeholders involved in planning for health system capacity and program budgeting for the early years of the ACA Medicaid expansions.