title: Anaemia as an independent key risk factor for major haemorrhage in patients treated with vitamin K antagonists: Results of the SCORE prospective cohort.
abstract: BACKGROUND
  Risk scores for the prediction of haemorrhage are poorly predictive of major bleeding. The aim of this study was to refine the estimation of bleeding risk by identifying one or several parameters of prognostic significance among these algorithms.
  
  
  METHODS
  The SCORE study was a prospective, multicentre cohort study conducted in France in 2009-2010. Patients were eligible if they had received vitamin K antagonist (VKA) for any therapeutic indication for at least 3months. The primary outcome was the occurrence of major bleeding at 1-year follow-up.
  
  
  RESULTS
  In total, 962 patients were included in this study and evaluated at 1year. The incidence of major bleeding at 1-year follow-up (Kaplan-Meier method) was 2.9% [95% confidence interval (CI) 1.9-4.2]. The rate of major bleeding was 8.2% (95 CI 3.4-16.2) per year in patients classified as high risk by at least four scores. In a multivariate Cox analysis, of the risk factors for the different scores, only anaemia <100g/l at inclusion was strongly associated with risk of major bleeding (hazard ratio 6.1, 95% CI 2.7-13.8, P<0.0001). Through an induction tree analysis performed to identify a common parameter in the majority of scores, anaemia was found to be the main predictor of correct classification as high risk by at least four scores (55% of patients classified as high risk by at least four scores vs 3.3% in the absence of anaemia).
  
  
  CONCLUSIONS
  Anaemia with haemoglobin <100g/l is the most important predictor of high risk of bleeding in patients treated with VKA.
authors.affiliation: Department of Vascular Medicine, University Hospital Grenoble-Alpes, Grenoble, France.
authors.forename: Nora
authors.initials: N
authors.lastname: Zenati
authors.affiliation: Department of General Medicine, University Hospital Grenoble-Alpes, Grenoble, France; CNRS/TIMC-IMAG UMR 5525/Themas, Grenoble-Alpes University, Grenoble, France.
authors.forename: Yoann
authors.initials: Y
authors.lastname: Gaboreau
authors.affiliation: Department of Vascular Medicine, University Hospital Grenoble-Alpes, Grenoble, France; CISSS Chaudières-Appalaches, site Hôtel Dieu de Lévis, Levis, Quebec, Canada.
authors.forename: Cynthia Brousseau
authors.initials: CB
authors.lastname: Provencher
authors.affiliation: CNRS/TIMC-IMAG UMR 5525/Themas, Grenoble-Alpes University, Grenoble, France; Department of Anaesthesiology, University Hospital Grenoble-Alpes, Grenoble, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Albaladejo
authors.affiliation: CNRS/TIMC-IMAG UMR 5525/Themas, Grenoble-Alpes University, Grenoble, France; Clinical Investigation Centre, University Hospital Grenoble-Alpes, Grenoble, France.
authors.forename: Jean Luc
authors.initials: JL
authors.lastname: Bosson
authors.affiliation: Department of Vascular Medicine, University Hospital Grenoble-Alpes, Grenoble, France; CNRS/TIMC-IMAG UMR 5525/Themas, Grenoble-Alpes University, Grenoble, France. Electronic address: GPernod@chu-grenoble.fr.
authors.forename: Gilles
authors.initials: G
authors.lastname: Pernod
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000150:complications*; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D005602:France / Q000453:epidemiology; D006470:Hemorrhage / Q000139:chemically induced* / Q000209:etiology; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D014812:Vitamin K / Q000037:antagonists & inhibitors*
chemical_list: D000925:Anticoagulants; D014812:Vitamin K
keywords: Anaemia; Bleeding scores; Major bleeding; Vitamin K antagonists