Volume-outcome relationships in the treatment of renal tumors.

PURPOSE: Outcomes of complex surgical procedures tend to be better for high volume providers, although this has not been clearly established for renal cell carcinoma. We determined the relationship of provider volume with partial nephrectomy and morbidity for renal cell carcinoma treatment.
MATERIALS AND METHODS: We performed a population based, observational study using data on 24,579 patients treated surgically for a renal mass from April 1998 to March 2008. Surgeon and hospital volume quartiles were created using the total number of nephrectomies during the 10-year observation period. The effect of provider volume on partial nephrectomy use, complications and mortality was determined by multivariable logistic regression adjusted for covariates.
RESULTS: Partial nephrectomy was done by 10.9% of low vs 24.7% of very high volume surgeons (p<0.0001). A modest decrease in complications was observed with increasing surgeon volume (low vs very high 37.6% vs 34.5%, p<0.0001). The effect of in-hospital mortality was more dramatic with a 1.71%, 1.20%, 0.97% and 0.92% rate for low, intermediate, high and very high volume surgeons, respectively (p<0.0001). After adjusting for covariates, compared to low volume surgeons patients treated by very high volume surgeons had 1.54 times the odds of undergoing partial nephrectomy (95% CI 1.37-1.72, p<0.0001), 0.84 times the odds of an in-hospital complication (95% CI 0.77-0.92, p<0.0001) and 0.69 times the odds of in-hospital death (95% CI 0.47-1.01, p=0.16).
CONCLUSIONS: Higher volume surgeons perform partial nephrectomy more often, show a lower complication rate and may have a lower in-hospital mortality rate than lower volume surgeons.