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Anesthesiology and Pain Management

Delphi-Consensus Weights for Ischemic and Bleeding Events to Be Included in a Composite Outcome for RCTs in Thrombosis Prevention
Published: Thursday, April 07, 2011
Author: Agnes Dechartres et al.

by Agnes Dechartres, Pierre Albaladejo, Jean Mantz, Charles Marc Samama, Jean-Philippe Collet, Philippe Gabriel Steg, Philippe Ravaud, Florence Tubach

Background and Objectives

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.


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.


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.


These ratings could be used to weight ischemic and bleeding events of various severity comprising a composite outcome in the field of thrombosis prevention.