Medical Care Utilization in an Experimental Prepaid Group Practice Model in a University Medical Center

Medical care utilization is reported for the first two years of an experimental prepaid group practice, the Medical Care Group of Washington University (MCG). Methodologic considerations are emphasized and comparison is made between prospectively selected study and control families. Overall, MCG children were admitted to hospitals less often than control children for surgical and nonsurgical conditions. For adults, reduced admission rates were found only for nonsurgical conditions. In contrast, surgical utilization by MCG enrollees was somewhat higher than control utilization in both years, but utilization of surgical services by both study and control enrollees was closer to that characteristic of prepaid group practice than it was to that of the general population. MCG members used significantly fewer hospital days than controls in year 2. In both years, members utilized ambulatory services at a rate about twice that of controls. Thus, the combination of a prepayment mechanism for ambulatory services with a system which guarantees provision of those services was associated with changes in the pattern of medical care delivery. Some, but not all, of these changes were characteristic of those predicted for prepaid group practice.