Ecology of access: Health care safety nets and use of care in 60 U.S. communities

Background: Health care safety-nets play key roles in providing health care to the underserved. Yet previous research suggests that safety-net providers vary in their ability to care for vulnerable persons. This paper addresses two related questions: What are the effects of state and local factors on local health care safety-net organizations' capacity to provide services? How does organizational safety-net capacity influence utilization among low-income uninsured adults?

Design: The first stage investigates the effects of state political ideology, state Medicaid funding and eligibility policy, local government revenues, and community uninsurance rates on safety net capacity in 276 communities, using diverse secondary data sources. The second question is answered by using a subset of 60 of these geographic areas to analyze the effects of predicted organizational safety-net capacity on use of care among low income uninsured adults, controlling for individual-level socio-demographic characteristics and local office-based physician supply. Data for the individual-level characteristics come from the 1996-1997 Community Tracking Study. Tobit estimations were performed to predict safety-net capacity and two-stage least squares regression with instrumental variables was used for the full model to address endogeneity bias.

Findings: More liberal state political ideology (p<.01), higher local government revenues (p<.001), and lower uninsurance rates (p<.05) were associated with greater organizational safety net capacity, and greater organizational capacity was associated with increased probability of use of care.

Implications: More liberal jurisdictions and those with greater fiscal resources displayed greater safety-net capacity and, ultimately, increased probability of use among low-income uninsured adults surveyed.