title: Regional and inter-hospital differences in the utilisation of liver surgery for patients with synchronous colorectal liver metastases in the Netherlands.
abstract: The objective of this study was to map referral patterns in patients with synchronous colorectal liver metastases (SCLM) and to investigate if type, volume and location of the hospital of diagnosis are associated with whether or not patients underwent liver resection.
  
  
  
  This population-based study includes all patients diagnosed with SCLM between 2008 and 2012, based on the Netherlands Cancer Registry. To study inter-hospital variation, the proportion of patients undergoing liver surgery was calculated per hospital of diagnosis. Multivariable multilevel logistic regression analysis was used to investigate the association between hospital characteristics and liver resection.
  
  
  
  Of 10,520 patients with SCLM, 12% (n = 1259) underwent liver surgery. Of these patients, 58% (n = 733) were referred to another hospital to undergo liver surgery. In 53% of the patients (n = 647), liver resection was performed in a university hospital, in 39% (n = 482) in a dedicated liver centre and in 8% (n = 102) in a general hospital. There was a large inter-hospital variation in the proportion of patients undergoing liver resection (2-26%). In a multilevel logistic regression model, the odds of undergoing liver surgery were higher when patients were diagnosed in hospitals where liver surgery was performed compared with the general hospitals (dedicated liver centre: odds ratio 1.36 [95% confidence intervals 1.08-1.70], university hospital: odds ratio 1.69 [95% confidence intervals 1.22-2.34]).
  
  
  
  There is a large inter-hospital and inter-regional variation in the utilisation of liver resection. Patients diagnosed with SCLM in expert centres had a higher chance of undergoing liver resection.
authors.affiliation: Department of Surgery, Radboud University Medical Center, Nijmegen, The Netherlands. Electronic address: Jorine.tLam-Boer@radboudumc.nl.
authors.forename: J
authors.initials: J
authors.lastname: 't Lam-Boer
authors.affiliation: Division of Surgical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
authors.forename: E P
authors.initials: EP
authors.lastname: van der Stok
authors.affiliation: Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Huiskens
authors.affiliation: Netherlands Comprehensive Cancer Organisation, Utrecht, The Netherlands.
authors.forename: R H A
authors.initials: RH
authors.lastname: Verhoeven
authors.affiliation: Department of Medical Oncology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: C J A
authors.initials: CJ
authors.lastname: Punt
authors.affiliation: Netherlands Comprehensive Cancer Organisation, Utrecht, The Netherlands.
authors.forename: M A G
authors.initials: MA
authors.lastname: Elferink
authors.affiliation: Department of Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: J H
authors.initials: JH
authors.lastname: de Wilt
authors.affiliation: Division of Surgical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Verhoef
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006498:Hepatectomy / Q000706:statistics & numerical data*; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary* / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*
keywords: Colorectal cancer; Inter-hospital differences; Liver metastases; Liver surgery; Stage IV