Use of nephrectomy at select medical centers - A case of follow the crowd?

Purpose: Regionalization of high risk surgical procedures to larger, teaching hospitals has been suggested as a means to improve the quality of care. We determined the extent to which the regionalization of nephrectomy has occurred and describe the potential causes and implications of any observed regionalization. Materials and Methods: The Nationwide Inpatient Sample comprises a 20% sampling of hospital discharges in the United States yearly. Patients undergoing nephrectomy for kidney cancer between 1988 and 2002 were identified using International Classification of Disease, Ninth Revision, Clinical Modification codes. Regionalization was assessed using 6 structural hospital measures, including teaching status, urban location, discharge volume, nephrectomy volume, bed capacity and for-profit status. Adjusted models were developed to identify the significance of temporal trends in each regionalization measure. Results: We identified 66,621 patients undergoing nephrectomy during the study period. Compared to procedures performed between 1988 and 1990 the likelihood of undergoing nephrectomy at teaching, high nephrectomy volume and high throughput (all diagnoses) hospitals increased by 2.0 (CI 1.9 to 2.2), 7.4 (CI 7.1 to 7.7) and 2.2 times (CI 2.1 to 2.2), respectively, in 2000 to 2002. Conversely nephrectomy was less likely to be performed at for-profit hospitals (OR 0.5, CI 0.5 to 0.6). Patients were more likely to undergo partial nephrectomy at teaching, high volume, high throughput, urban hospitals. Conclusions: Regionalization of nephrectomy to teaching and high volume (nephrectomy and all diagnoses) hospitals is currently under way. Although the implications are not entirely clear, this study provides further evidence for the crowding of complex surgical procedures into these institutions.