title: Mortality after surgery in Europe: a 7 day cohort study.
abstract: BACKGROUND
  Clinical outcomes after major surgery are poorly described at the national level. Evidence of heterogeneity between hospitals and health-care systems suggests potential to improve care for patients but this potential remains unconfirmed. The European Surgical Outcomes Study was an international study designed to assess outcomes after non-cardiac surgery in Europe.
  
  
  METHODS
  We did this 7 day cohort study between April 4 and April 11, 2011. We collected data describing consecutive patients aged 16 years and older undergoing inpatient non-cardiac surgery in 498 hospitals across 28 European nations. Patients were followed up for a maximum of 60 days. The primary endpoint was in-hospital mortality. Secondary outcome measures were duration of hospital stay and admission to critical care. We used χ(2) and Fisher's exact tests to compare categorical variables and the t test or the Mann-Whitney U test to compare continuous variables. Significance was set at p<0·05. We constructed multilevel logistic regression models to adjust for the differences in mortality rates between countries.
  
  
  RESULTS
  We included 46,539 patients, of whom 1855 (4%) died before hospital discharge. 3599 (8%) patients were admitted to critical care after surgery with a median length of stay of 1·2 days (IQR 0·9-3·6). 1358 (73%) patients who died were not admitted to critical care at any stage after surgery. Crude mortality rates varied widely between countries (from 1·2% [95% CI 0·0-3·0] for Iceland to 21·5% [16·9-26·2] for Latvia). After adjustment for confounding variables, important differences remained between countries when compared with the UK, the country with the largest dataset (OR range from 0·44 [95% CI 0·19-1·05; p=0·06] for Finland to 6·92 [2·37-20·27; p=0·0004] for Poland).
  
  
  CONCLUSIONS
  The mortality rate for patients undergoing inpatient non-cardiac surgery was higher than anticipated. Variations in mortality between countries suggest the need for national and international strategies to improve care for this group of patients.
  
  
  BACKGROUND
  European Society of Intensive Care Medicine, European Society of Anaesthesiology.
authors.affiliation: Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK. r.pearse@qmul.ac.uk
authors.forename: Rupert M
authors.initials: RM
authors.lastname: Pearse
authors.forename: Rui P
authors.initials: RP
authors.lastname: Moreno
authors.forename: Peter
authors.initials: P
authors.lastname: Bauer
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.forename: Philipp
authors.initials: P
authors.lastname: Metnitz
authors.forename: Claudia
authors.initials: C
authors.lastname: Spies
authors.forename: Benoit
authors.initials: B
authors.lastname: Vallet
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
authors.forename: Andreas
authors.initials: A
authors.lastname: Hoeft
authors.forename: Andrew
authors.initials: A
authors.lastname: Rhodes
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003422:Critical Care / Q000706:statistics & numerical data; D005060:Europe / Q000453:epidemiology; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods / Q000706:statistics & numerical data; D013514:Surgical Procedures, Operative / Q000401:mortality*; D016896:Treatment Outcome