Regional availability of high-volume hospitals for major surgery.

Despite evidence of increased risks, a large number of patients still have surgery in low-volume hospitals. To better understand why, we used Medicare data to study the regional availability of high-volume hospitals. More than half of patients undergoing three procedures in low-volume hospitals lived in regions lacking a high-volume hospital. Some regions simply lacked enough cases to support a high-volume hospital. Other regions had enough cases but too many hospitals performing them. Although consolidation of surgical services may be feasible in some settings, volume-based referral strategies are impractical for many U.S. regions.