title: Are outcome-adaptive allocation trials ethical?
abstract: Randomization is firmly established as a cornerstone of clinical trial methodology. Yet, the ethics of randomization continues to generate controversy. The default, and most efficient, allocation scheme randomizes patients equally (1:1) across all arms of study. However, many randomized trials are using outcome-adaptive allocation schemes, which dynamically adjust the allocation ratio in favor of the better performing treatment arm. Advocates of outcome-adaptive allocation contend that it better accommodates clinical equipoise and promotes informed consent, since such trials limit patient-subject exposure to sub-optimal care. In this essay, we argue that this purported ethical advantage of outcome-adaptive allocation does not stand up to careful scrutiny in the setting of two-armed studies and/or early-phase research.
authors: Studies of Translation, Ethics and Medicine (STREAM), Biomedical Ethics Unit, McGill University, Montréal, QC, Canada.
authors: Spencer Phillips
authors: SP
authors: Hey
authors: Studies of Translation, Ethics and Medicine (STREAM), Biomedical Ethics Unit, McGill University, Montréal, QC, Canada jonathan.kimmelman@mcgill.ca.
authors: Jonathan
authors: J
authors: Kimmelman
mesh_terms: D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000941:ethics*; D012107:Research Design
keywords: Adaptive randomization; equipoise; ethics; therapeutic misconception
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