Background. Reports of better results at national referral centers than at
low-volume community hospitals have prompted calls for regionalizing pancre
aticoduodenectomy (the Whipple procedure). We examined the relationship bet
ween hospital volume and mortality with this procedure across all US hospit
als.
Methods. Using information form the Medicare claims database, we performed
a national cohort study of 7229 Medicare patients more than 65 years old un
dergoing pancreaticoduodenectomy between 1992 and 1995. We divided the stud
y 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 lo
gistic regression to account for potentially confounding patient characteri
stics, we examined the association between institutional volume and in-hosp
ital mortality, our primary outcome measure.
Results. More than 50% of Medicare patients undergoing pancreaticoduodenect
omy received care at hospitals performing fewer than 2 such procedures per
year. In-hospital mortality rates at these low- and very-low-volume hospita
ls were 3- to 4-fold higher than at high-volume hospitals (12% and 16%, res
pectively, vs 4%, P<.001). Within the high-volume quartile, the 10 hospital
s with the nation's highest volumes had lower mortality rates than the rema
ining high-volume centers (2.1% vs 6.2%, P<.01). The strong association bet
ween 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 m
any complex surgical procedures, hospital experience is particularly import
ant with pancreaticoduodenectomy. Patients considering this procedure shoul
d be given the option of care at a high-volume referral center.