Hospital volume and 90-day mortality risk after radical cystectomy: a population-based cohort study.

Background: Hospital cystectomy volume has been associated with in-hospital perioperative mortality in previous studies. In this study, we examine the relationship between hospital cystectomy volume and 90-day mortality in a population-based cohort of patients undergoing cystectomy for bladder cancer. Methods: We performed a retrospective cohort study using population from the State of Washington Comprehensive Hospital Abstract Reporting System (CHARS) database. We examined the association between hospital cystectomy volume (categorized into volume tertiles) and cumulative 90-day mortality in patients undergoing cystectomy for bladder cancer. Multivariate regression was used to adjust for patient age, comorbid disease, year of surgery, and gender. Standard errors were clustered by discharge hospital. Results: We identified 823 patients who underwent cystectomy for bladder cancer at 39 unique hospitals in 2003-2007. The unadjusted cumulative 90-day cumulative mortality was 5.4, 6.9, and 8.4% for patients discharged from hospitals in the high, medium, and low volume tertiles, respectively ( P = 0.35). In the multivariate analysis, the patients undergoing cystectomy who were discharged from hospitals in the highest volume tertile had a lower risk of death in the first 90 days postoperatively compared to patients discharged from hospitals in the low volume tertile, though the finding was not statistically significant (OR = 0.68, 95% CI 0.29-1.56). Conclusions: Ninety-day cumulative mortality after cystectomy for bladder cancer is significant and may be associated with hospital cystectomy volume. [ABSTRACT FROM AUTHOR]