Effect of hospital volume on in-hospital mortality with pancreaticoduodenectomy

Background. Reports of better results at national referral centers than at low-volume community hospitals have prompted calls for regionalizing pancreaticoduodenectomy (the Whipple procedure). We examined the relationship between hospital volume and mortality with this procedure across all US hospitals. Methods. Using information form the Medicare claims database, we performed a national cohort study of 7229 Medicare patients more than 65 years old undergoing pancreaticoduodenectomy between 1992 and 1995. We divided the study population into approximate quartiles according to the hospital's average annual volume of pancreaticoduodenectomies in Medicare patients: very low (<1/y), low (1-2/y), medium (2-5/y), and high (5+/y). Using multivariate logistic regression to account for potentially confounding patient characteristics, we examined the association between institutional volume and in-hospital mortality, our primary outcome measure. Results. More than 50% of Medicare patients undergoing pancreaticoduodenectomy received care at hospitals performing fewer than 2 such procedures per year. In-hospital mortality rates at these low- and very-low-volume hospitals were 3- to 4-fold higher than at high-volume hospitals (12% and 16%, respectively, vs 4%, P<.001). Within the high-volume quartile, the 10 hospitals with the nation's highest volumes had lower mortality rates than the remaining high-volume centers (2.1% vs 6.2%, P<.01). The strong association between institutional volume and mortality could not be attributed to patient case-mix differences or referral bias. Conclusions. Although volume-outcome relationships have been reported for many complex surgical procedures, hospital experience is particularly important with pancreaticoduodenectomy. Patients considering this procedure should be given the option of care at a high-volume referral center.