title: Impact of nationwide centralization of pancreaticoduodenectomy on hospital mortality.
abstract: BACKGROUND
  The impact of nationwide centralization of pancreaticoduodenectomy (PD) on mortality is largely unknown. The aim of this study was to analyse changes in hospital volumes and in-hospital mortality after PD in the Netherlands between 2004 and 2009.
  
  
  METHODS
  Nationwide data on International Classification of Diseases, ninth revision (ICD-9) code 5-526 (PD, including Whipple), patient age, sex and mortality were retrieved from the independent nationwide KiwaPrismant registry. Based on established cut-off points of annually performed PDs, hospitals were categorized as very low (fewer than 5), low (5-10), medium (11-19) or high (at least 20) volume. A subgroup analysis based on a cut-off age of 70 years was also performed.
  
  
  RESULTS
  Some 2155 PDs were included. The number of hospitals performing PD decreased from 48 in 2004 to 30 in 2009 (P = 0·011). In these specific years, the proportion of patients undergoing PD in a medium- or high-volume centre increased from 52·9 to 91·2 per cent (P < 0·001). Nationwide mortality rates after PD decreased from 9·8 to 5·1 per cent (P = 0·044). The mortality rate during the 6-year period was 14·7, 9·8, 6·3 and 3·3 per cent in very low-, low-, medium- and high-volume hospitals respectively (P < 0·001). The difference in mortality between medium- and high-volume centres was statistically significant (P = 0·004). The volume-outcome relationship was not influenced by age (P = 0·467). The mortality rate after PD in patients aged at least 70 years was 10·4 per cent compared with 4·4 per cent in younger patients (P < 0·001).
  
  
  CONCLUSIONS
  With nationwide centralization of PD, the in-hospital mortality rate after this procedure decreased. Further centralization of PD is likely to decrease mortality further, especially in the elderly.
authors.affiliation: Department of Surgery, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: R F
authors.initials: RF
authors.lastname: de Wilde
authors.forename: M G H
authors.initials: MG
authors.lastname: Besselink
authors.forename: I
authors.initials: I
authors.lastname: van der Tweel
authors.forename: I H J T
authors.initials: IH
authors.lastname: de Hingh
authors.forename: C H J
authors.initials: CH
authors.lastname: van Eijck
authors.forename: C H C
authors.initials: CH
authors.lastname: Dejong
authors.forename: R J
authors.initials: RJ
authors.lastname: Porte
authors.forename: D J
authors.initials: DJ
authors.lastname: Gouma
authors.forename: O R C
authors.initials: OR
authors.lastname: Busch
authors.forename: I Q
authors.initials: IQ
authors.lastname: Molenaar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002497:Centralized Hospital Services / Q000706:statistics & numerical data; D005260:Female; D006276:Health Facility Size / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D016577:Pancreaticoduodenectomy / Q000401:mortality* / Q000706:statistics & numerical data; D012307:Risk Factors; D015996:Survival Rate; D055815:Young Adult