Publications by Peter Cunningham for Health Policy Center

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We used instrumental variable analysis to account for the endogeneity of safety net provider location in estimating multivariate regression models of the relationship between safety net location and access to care of uninsured persons. Data were from the 1998–99 Community Tracking Household Survey. We found that closer proximity to safety net providers increases access to care for the uninsured. Failure to account for endogeneity bias leads to a finding of no effect of the safety net on access. However, improvements in access associated with greater safety net availability still leave a substantial gap in access between the uninsured and the insured. (Health Services Research 339(5): 1527–46.)

After slow growth during much of the 1990's, Medicaid physician fees increased, on average, by 27.4 percent between 1998 and 2003. The greatest growth occurred for primary care fees. States with the lowest relative fees in 1998 increased their fees the most, but almost no states changed their position relative to other states or Medicare. Physicians in states with the lowest Medicaid fees were less willing to accept most or all new Medicaid patients in both 1998 and 2003. However, large fee increases were associated with an increased willingness of primary care physicians to accept new Medicaid patients (Health Affairs Web Exclusive, June 23, 2004.)

The State Children’s Health Insurance Program (SCHIP) was designed to increase the number of children with health insurance coverage without resulting in large numbers of children substituting public coverage for private coverage. This study uses data from the Community Tracking Study collected before and after SCHIP implementation to examine effects of increases in eligibility for public coverage on children’s health insurance coverage. Using a regression-based difference-in-differences approach, we find that increases in eligibility for public coverage did increase the likelihood of having Medicaid or other state coverage versus being uninsured for the primary SCHIP target population – children in families with incomes between 100 and 200 percent of the federal poverty level. However, eligibility increases also increases the likelihood of having public coverage versus private insurance for this income group, indicating that SCHIP expansions resulted in substitution of public for private insurance. In fact, simulation results indicate that the initial impact of SCHIP on private insurance coverage has been far greater than on uninsurance rates. These results reflect the early stages of SCHIP implementation, however, and are subject to change as the SCHIP program matures. (Medical Care Research and Review 2002 December; 59(4): 359-383).

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