Regionalization of percutaneous nephrolithotomy: evidence for the increasing burden of care on tertiary centers

The regionalization of procedures to specialized medical centers has been suggested as a means to improve the quality of care for select high risk procedures. Prior work has demonstrated the spontaneous regionalization of high risk procedures to tertiary centers. Similar concentration of complex, low risk procedures (e.g. percutaneous nephrolithotomy) to these centers would underscore the increasing burden of care placed on these hospitals.

We used the Nationwide Inpatient Sample to identify 12,948 patients who underwent percutaneous nephrolithotomy for stones between 1988 and 2002. Regionalization was measured based on the 6 structural hospital qualities of teaching status, urban location, bed capacity, hospital throughput (all diagnoses), annual percutaneous nephrolithotomy volume and for-profit status. Logistic regression was used to determine the propensity of percutaneous nephrolithotomy to concentrate to these medical centers.

Compared to procedures performed between 1988 and 1990, patients were more likely to undergo percutaneous nephrolithotomy at teaching (OR 1.6, 95% CI 1.3-1.9), high percutaneous nephrolithotomy volume (OR 1.7, 95% CI 1.6-1.9), large bed capacity (OR 1.2, 95% CI 1.1-1.3) and high throughput hospitals (OR 1.4, 95% CI 1.3-1.4) in the years 2000 to 2002.

Percutaneous nephrolithotomy, a technically complex but low risk procedure, has spontaneously regionalized to tertiary centers, suggesting the migration of complex surgical care to these centers. The impact of this increasing burden of care on tertiary centers is unclear but may be problematic in the current reimbursement environment.