title: Hospital variability in postoperative mortality after rectal cancer surgery in the Spanish Association of Surgeons project: The impact of hospital volume.
abstract: OBJECTIVE
  This multicentre observational study examines variation between hospitals in postoperative mortality after elective surgery in the Rectal Cancer Project of the Spanish Society of Surgeons and explores whether hospital volume and patient characteristics contribute to any variation between hospitals.
  
  
  METHODS
  Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all rectal adenocarcinomas operated by an anterior resection or an abdominoperineal excision at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, tumour location and stage, administration of neoadjuvant treatment, and annual volume of surgical procedures.
  
  
  RESULTS
  A total of 9809 consecutive patients were included. The rate of 30-day postoperative mortality was 1.8% Stratified by annual surgical volume hospitals varied from 1.4 to 2.0 in 30-day mortality. In the multilevel regression analysis, male gender (OR 1.623 [1.143; 2.348]; P<.008), increased age (OR: 5.811 [3.479; 10.087]; P<.001), and ASA score (OR 10.046 [3.390; 43.185]; P<.001) were associated with 30-day mortality. However, annual surgical volume was not associated with mortality (OR 1.309 [0.483; 4.238]; P=.619). Besides, there was a statistically significant variation in mortality between all departments (MOR 1.588 [1.293; 2.015]; P<.001).
  
  
  CONCLUSIONS
  Postoperative mortality varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume.
authors.affiliation: Departamento Ciencias de la Salud, Universidad Pública de Navarra, Pamplona, España. Electronic address: hortiz.24e@gmail.com.
authors.forename: Héctor
authors.initials: H
authors.lastname: Ortiz
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Hospital Universitario de Bellvitge, Barcelona, España.
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Biondo
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Hospital Universitario Josep Trueta, Gerona, España.
authors.forename: Antonio
authors.initials: A
authors.lastname: Codina
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Complejo Hospitalario de Navarra, Pamplona, España.
authors.forename: Miguel Á
authors.initials: MÁ
authors.lastname: Ciga
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Hospital Universitario Donostia, San Sebastián, España.
authors.forename: José M
authors.initials: JM
authors.lastname: Enríquez-Navascués
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Hospital Universitario Vall d'Hebron, Barcelona, España.
authors.forename: Eloy
authors.initials: E
authors.lastname: Espín
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Hospital Universitario La Fe, Valencia, España.
authors.forename: Eduardo
authors.initials: E
authors.lastname: García-Granero
authors.affiliation: Unidad de Coloproctología, Departamento de Cirugía, Hospital General Universitario de Valencia, Valencia, España.
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Roig
mesh_terms: D017558:Elective Surgical Procedures; D006761:Hospitals; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012004:Rectal Neoplasms; D016896:Treatment Outcome
keywords: 30-day mortality; Base de datos multicéntrica; Case-mix; Comparación de hospitales; Comparison of departments; Cáncer de recto; Docencia; Education; Mortalidad postoperatoria; Multicentre database; Rectal cancer; Volumen quirúrgico anual