Defining the minimum hospital case-load to achieve optimum outcomes in radical cystectomy

To define 'high-' and 'low-' volume hospitals for radical cystectomy, and the minimum caseload required for a hospital to achieve optimum outcomes, as a relationship between increasing surgical case volume and improved outcomes in radical urological surgery has been suggested in recent North American studies.

All cystectomies for urological cancer in England over 5 years were analysed from Hospital Episode Statistics (HES) data. The data were analysed statistically to describe the relationship between each hospital's annual case volume and two outcome measures: in-hospital mortality rate (MR) and hospital stay.

In all, there were 6317 cystectomies in 210 centres, with an overall MR of 5.6%. There was a significant inverse correlation (-0.733, P < 0.01) between hospital case volume and MR. Applying 95% confidence intervals, the minimum caseload required to achieve optimum outcomes was 11 procedures/year. Increasing the caseload beyond this minimum did not produce a significant reduction in MR.

Analysis of HES data confirms an inverse relationship between hospital caseload and mortality for radical cystectomy. A caseload of 11 operations/year is associated with the lowest MR.