The volume-outcome relationship for radical cystectomy in England: an analysis of outcomes other than mortality

Objective: •To evaluate the volume-outcome relationship for radical cystectomy in England using outcomes other than mortality.

Patients and methods: •Patients undergoing an elective radical cystectomy were extracted from administrative hospital data for financial years 2000/1 to 2006/7. •Institutional and surgeon volume was assessed against postoperative re-intervention, postoperative complications and emergency readmission within 28 days, using a set of models accounting for patient case-mix, the 'clustered' nature of the data and structural and process of care measures.

Results: •In the final model, the odds of re-intervention within 14 and 30 days of operation for medium-volume institutions compared to low-volume institutions were found to be 63% (odds ratio, OR, 1.63; 95% CI 1.15-2.32; P= 0.01) and 52% (OR, 1.52; 95% CI, 1.13-2.04; P= 0.01) higher, respectively. •In the summary of adjusted probabilities, low-volume institutions appeared to have a lower re-intervention rate than both medium- and high-volume institutions. •By contrast, high-volume surgeons were associated with a reduced odds (OR, 0.68; 95% CI, 0.51-0.91; P= 0.01) of early re-intervention (within 14 days) compared to low-volume surgeons. •This surgeon volume-outcome effect became apparent only after adjusting for the influence of the institution and structural and process of care confounders. •There was no statistically significant relationship between volume and complication or readmission rates.

Conclusions: •Radical cystectomy measures of re-intervention rates can be used as outcome measures to discern differences across institutional or surgeon volume providers when the institutional and surgeon volume are co-examined and adjustment for structural and process of care confounders is performed. •The finding of a lower risk of re-intervention in low-volume institutions needs to be explored further.