The long-term effects of Medicaid managed care on obstetrics care in three California counties.

OBJECTIVE: To evaluate the long-term effects of Medicaid managed care (MMC) on obstetric service use and program costs in California.

DATA SOURCES/STUDY SETTING: Longitudinal administrative data on Medi-Cal enrollment and claims and encounters related to pregnancy and delivery services were gathered from three counties--two long-standing MMC counties and one traditional fee-for-service Medicaid county--in California between 1987 and 1992.

STUDY DESIGN: We studied Aid to Families with Dependent Children (AFDC) beneficiaries with live singleton vaginal deliveries with associated hospital stays of 14 days or less. Effects of managed care were examined with respect to prenatal visits, length of stay for delivery, maternal postpartum readmission rates, and total program expenditures. Multivariate analyses examined how the relative effect of managed care on service use and program expenditures in each MMC county evolves over time in comparison to fee-for-service. We controlled for length of Medi-Cal enrollment prior to delivery, data censoring, and individual characteristics such as race and age.

PRINCIPAL FINDINGS: Prenatal care use is consistently lower in the MMC counties, although all three counties' prenatal care provision is well below the national standard. Drastic increases in one-day-stay deliveries were found: up to almost 50 percent of deliveries in MMC counties were one-day stays. Program cost savings associated with MMC enrollment are unambiguous.

CONCLUSIONS: MMC cost savings might have come at the expense of reduced provision of prenatal care and shorter delivery length of stay. Future studies should verify any possible causal link and the effects on maternal and infant health outcomes.