Antitrust pitfalls in outpatient services.

Increasingly, services traditionally provided to inpatients are moving to the outpatient setting, resulting in greater antitrust risk. Antitrust issues are most likely to arise when a hospital with a large share of the inpatient market attempts to increase outpatient volume by restricting their patients' choices of outpatient providers, or when providers who control scarce outpatient resources attempt to restrict competition by denying other providers access to a facility. This trend has affected physicians both as competitors of hospitals in the outpatient services market and as participants with hospitals in ventures for the provision of outpatient care.