Comparison of cesarean section rates in fee-for-service versus managed care patients in the Ohio Medicaid population, 1992-1997.

OBJECTIVE: To examine changes over time in the cesarean section rates for fee-for-service (FFS) beneficiaries versus enrollees of managed care programs (MCPs) in the Ohio Medicaid population. STUDY
DESIGN: Cross-sectional study using linked Ohio birth certificates and Medicaid files. PATIENTS AND METHODS: Study patients were Medicaid-enrolled residents of urban counties who had singleton, live births from 1992 through 1997 (n = 86,459). Changes in primary and repeat cesarean section rates were analyzed in the FFS and MCP groups. The test of homogeneity of odds ratios was used to measure the statistical difference between unadjusted odds ratios. Logistic regression analysis was conducted to adjust for risk factors.
RESULTS: From 1992 to 1997, the difference in the rates of primary and repeat cesarean sections between FFS and MCP patients decreased. The unadjusted odds ratio (OR) increased from 0.66 to 0.81 (P = .06) for primary cesarean sections and from 0.67 to 1.04 (P = .03) for repeat cesarean sections; this indicated that the likelihood of undergoing a cesarean section increased over time for MCP enrollees compared with FFS beneficiaries. The results of the multivariate analysis indicated that the interaction term of payment source by year was not significant for primary cesarean sections (adjusted OR = 0.93; 95% confidence interval = 0.83, 1.04), but was highly significant for repeat cesarean sections (adjusted OR = 0.53; 95% confidence interval = 0.44, 0.64).
CONCLUSION: We observed a reduction in the difference between the rates of both primary and repeat cesarean sections in FFS and MCP patients over time. The reduction was not statistically significant for primary cesarean sections. For repeat cesarean sections, however, we observed a convergence of the rates for FFS and MCP patients.