title: Statistical considerations when using a composite endpoint for comparing treatment groups.
abstract: When comparing two treatment groups in a time-to-event analysis, it is common to use a composite event consisting of two or more distinct outcomes. The goal of this paper is to develop a statistical methodology to derive efficiency guidelines for deciding whether to expand a study primary endpoint from E1 (for example, non-fatal myocardial infarction and cardiovascular death) to the composite of E1 and E2 (for example, non-fatal myocardial infarction, cardiovascular death or revascularisation). We investigate this problem by considering the asymptotic relative efficiency of a log-rank test for comparing treatment groups with respect to a primary relevant endpoint E1 versus the composite primary endpoint, say E, of E1 and E2, where E2 is some additional endpoint.
authors.affiliation: Universitat Politècnica de Catalunya, Barcelona, Spain. lupe.gomez@upc.edu
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Gómez
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Lagakos
mesh_terms: D016915:AIDS Vaccines / Q000008:administration & dosage; D054058:Acute Coronary Syndrome / Q000150:complications / Q000188:drug therapy / Q000401:mortality; D019380:Anti-HIV Agents / Q000008:administration & dosage; D000924:Anticholesteremic Agents / Q000627:therapeutic use; D056808:Biostatistics / Q000379:methods*; D023381:Endpoint Determination / Q000706:statistics & numerical data*; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology; D006801:Humans; D011341:Probucol / Q000031:analogs & derivatives / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*
chemical_list: D016915:AIDS Vaccines; D019380:Anti-HIV Agents; D000924:Anticholesteremic Agents; C098825:HIV-1 immunogen, incomplete Freund's adjuvant; C471047:succinobucol; D011341:Probucol