It is well known that surgical volume positively correlates with improved mortality following surgical procedures. This is also evident following radical cystectomy. Still, it is not clear which factor plays a larger role in driving improved outcomes, hospital or surgeon volume. To clarify the relative contribution of each, Dr. Waingankar and colleagues performed a retrospective study on short- term mortality (<90 days) following radical cystectomy using the national tumor registry.
The authors queried the National Cancer Database for patients undergoing radical cystectomy and calculated the average hospital and surgeon value using reported specific surgeon NPI numbers. The association between hospital volume and surgeon volume with short-term mortality at 30, 60 and 90 days were evaluated using propensity scored weights and a proportional hazards regression model.
The authors identified 19,436 patients who underwent RC performed by 2,927 surgeons at 927 hospitals between 2010 and 2013. Median HV was 12.3 cases/ year and mean SV was 4.3 cases/ year. Hospitals with HV >30 cases/year had significantly lower 30- day mortality (1.9% vs. 3.4% for hospitals with <5 cases/ year, p<0.0001). Surgeons with >30/cases per year also had significantly reduced mortality (1.9%, p=0.04). Similar trends were observed at 60 and 90 days. Analysis of maximum likelihood estimates revealed that HV centers are more strongly associated with improved mortality outcomes than SV (Chi-square= 15.21, p<0.001).
The authors conclude that the above study argues in favor of regionalization where high volume centers can support improved outcomes through robust infrastructural and process based delivery of surgical care.
Comments from the audience: It was suggested that this study must be interpreted with a number of biases in mind. Retrospective data-base analysis of this nature neglects to account for the number of centers that are tertiary, the relative performance of low versus high complexity cases at each center, and a relatively high prevalence of low volume surgeons and centers.
Presented by Nikhil Waingankar, Philadelphia, PA
Written for UroToday by: Simone Vernez; Medical Student, Department of Urology, University of California, Irvine at the AUA 2016.