Relationship between hospital volume and late survival after pancreaticoduodenectomy

Background. Several studies have reported lower perioperative mortality rat es with pancreaticoduodenectomy at high-volume hospitals than at low-volume hospitals. We sought to determine whether volume is also related to surviv al after hospital discharge. Methods, Using information from the Medicare claims database, we performed a retrospective cohort study of all 7229 patients over age 65 undergoing pa ncreaticoduodenectomy in the United States between 1992 and 1995. We divide d the study population into approximate quartiles according to their hospit al's average annual volume of pancreaticoduodenectomy in Medicine patients: very low (<1/y), low (1-2/y), medium (2-5/y), and high (5+/y). To adjust f or potentially confounding variables, we used a Cox proportional hazards mo del to examine relationships between hospital volume and mortality, our pri mary outcome measure. Results. Overall, 3-year survival was higher at high-volume centers (37%) t han at medium- (29%), low- (26%), and very low volume hospitals (25%) (log- rank P < .0001). After excluding perioperative deaths and adjusting for cas e-mis patients undergoing surgery at high-volume hospitals remained less li kely to experience late mortality than patients at very low volume centers (adjusted hazard ratio 0.69, 95% CI 0.62-0.76). Relationships between hospi tal volume and survival after discharge were not ? restricted to patients w ith cancer diagnoses, patients with benign disease had similar improvements in late survival after surgery at high-volume centers. Conclusions. Hospital volume strongly influences both perioperative risk an d long-tnm survival after pancreaticoduodenectomy. Our data suggest that bo th patient selection and differences in quality of care may underlie better outcomes at high-volume referral centers.