title: Delphi-consensus weights for ischemic and bleeding events to be included in a composite outcome for RCTs in thrombosis prevention.
abstract: OBJECTIVE
  To weight ischemic and bleeding events according to their severity to be used in a composite outcome in RCTs in the field of thrombosis prevention.
  
  
  METHODS
  Using a Delphi consensus method, a panel of anaesthesiology and cardiology experts rated the severity of thrombotic and bleeding clinical events. The ratings were expressed on a 10-point scale. The median and quartiles of the ratings of each item were returned to the experts. Then, the panel members evaluated the events a second time with knowledge of the group responses from the first round. Cronbach's a was used as a measure of homogeneity for the ratings. The final rating for each event corresponded to the median rating obtained at the last Delphi round.
  
  
  RESULTS
  Of 70 experts invited, 32 (46%) accepted to participate. Consensus was reached at the second round as indicated by Cronbach's a value (0.99 (95% CI 0.98-1.00)) so the Delphi was stopped. Severity ranged from under-popliteal venous thrombosis (median = 3, Q1 = 2; Q3 = 3) to ischemic stroke or intracerebral hemorrhage with severe disability at 7 days and massive pulmonary embolism (median = 9, Q1 = 9; Q3 = 9). Ratings did not differ according to the medical specialty of experts.
  
  
  CONCLUSIONS
  These ratings could be used to weight ischemic and bleeding events of various severity comprising a composite outcome in the field of thrombosis prevention.
authors.affiliation: UMR-S 738, INSERM, Paris, France.
authors.forename: Agnes
authors.initials: A
authors.lastname: Dechartres
authors.forename: Pierre
authors.initials: P
authors.lastname: Albaladejo
authors.forename: Jean
authors.initials: J
authors.lastname: Mantz
authors.forename: Charles Marc
authors.initials: CM
authors.lastname: Samama
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Collet
authors.forename: Philippe Gabriel
authors.initials: PG
authors.lastname: Steg
authors.forename: Philippe
authors.initials: P
authors.lastname: Ravaud
authors.forename: Florence
authors.initials: F
authors.lastname: Tubach
mesh_terms: D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use; D006470:Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007511:Ischemia / Q000175:diagnosis* / Q000209:etiology; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000175:diagnosis / Q000209:etiology; D013927:Thrombosis / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D001241:Aspirin