Obstetrical care under capitation.

Abstract

The purpose of the study was to evaluate the costs and outcomes of obstetrical care delivered to patients insured under capitation in comparison to care provided by the same practitioners to patients insured in the Blue Cross fee-for-service (FFS) model. In 1997, a change occurred in the reimbursement methodology used to pay obstetricians who cared for 93,000 members of an IPA-model HMO, Care Choices. This change, from FFS to capitation, was prototypical of managed care related innovations in health care financing and delivery. The method used for the primary analysis was a non-equivalent control group design. Because of potential spillover effects between patient groups, the estimates provide a lower bound. However, several other studies have found that patients with different insurance types are treated differently, holding physician or setting constant. Claims data for approximately 3,200 women, before and after the implementation of capitation, provided information on resource use. Use of selected services and hospital length of stay were measured. Satisfaction data was based on surveys of 550 women before and after the implementation of capitation. Findings and conclusions were that the costs and resource utilization for obstetrics care continued to decrease over time. Some of the national findings were in contrast to this finding. Both hospital length of stay and cesarean section rates increased during the study period on a national basis. They also increased for patients in this study but the length of stay increase was specific to Care Choices patients only. The decrease for the patients whose insurance had capitated the physicians was not significantly different for costs, usage of triage services or number of ultrasounds. However, it was significantly different and increased for hospital length of stay. In conclusion, there were a number of reasons why the differences between the two products were not significant. These include: (1) Spillover effects of capitation from one product to the other; (2) Differences in patient responsibility for costs between the two insurance products; (3) Impact of national legislation on length of stay; and (4) Impact of global capitation of the physician hospital organization (PHO) of which these physicians were a part.