Thursday, February 23
PS1 Poster Session 1 and Opening Mixer Thu, Feb 23, 5:30 PM - 7:00 PM
Conference Center AB

An Application of Competing Risk Analysis in Large Cardiovascular Clinical Trials (303443)

*Purva Jain, Beth Israel Deaconess Medical Center, Harvard Medical School 
Doug Arbetter, Beth Israel Deaconess Medical Center, Harvard Medical School 
Megan Yee, Beth Israel Deaconess Medical Center, Harvard Medical School 
Adrian F Hernandez, Duke University 
Russell D Hull, The University of Calgary 
Samuel Z Goldhaber, Brigham and Women's Hospital 
Robert A Harrington, Stanford University 
Alexander Gold, Portola Pharmaceuticals Inc. 
Alexander T Cohen, Guy's and St. Thomas' Hospital 
C. Michael Gibson, Harvard Medical School 

Keywords: competing risks, proportional hazards, cardiology, clinical trial

Competing risk methods are time to event analyses that include fatal and/or non-fatal events that may potentially alter or prevent a subject from experiencing the primary endpoint. This method provides a more accurate and less biased probability, but is rarely applied in cardiology trials. APEX investigated the efficacy of betrixaban versus enoxaparin to prevent venous thromboembolism (VTE) in acute medically ill patients (n=7513). The aim of the current analysis was to determine the efficacy of betrixaban vs enoxaparin accounting for non-VTE related death using the Fine & Gray method for competing risks. The proportion of non-VTE related death was similar in both the betrixaban (133, 3.6%) and enoxaparin (136, 3.7%) arms. The strength of association between treatment and efficacy was measured using a subhazard ratio, and the results favored betrixaban in the reduction of the secondary endpoint, a composite of symptomatic DVT, PE or VTE-related death (SR = 0.65, 95% 0.42 – 0.99, p=0.046). This method provides a less biased relationship between treatment and efficacy compared to a traditional cause-specific analysis that may overestimate the true strength of association.