Effect of hospital-based primary care setting on internists' use of inpatient hospital resources.

Hospital-based primary care is expanding, yet the impact of the hospital setting on physician practice patterns and health care costs is unknown. This project compared the use of inpatient hospital resources between internists practicing in hospital-based and freestanding primary care clinics. All hospitalizations over a two-year period by internists in the Kaiser-Permanente Medical Care Program--Oregon Region were analyzed ( n = 5,623). Organizational and financial incentives were uniform for all internists. Results indicate that hospital-based internists use inpatient resources differently from other internists. The former are more likely to hospitalize, but their patients are likely to have a shorter length of stay and fewer laboratory tests or consultations. On average, the hospital-based internists used 44 more hospital days for every 1,000 doctor office visits than did other internists, suggesting the policy makers need to consider the influence of the hospital setting on the level of inpatient utilization. Further research on the causality of this relationship and its generalizability appears a strong priority.