Equipoise in Clinical Trials
Angst and Progress
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The requirement that clinician-investigators need to have equipoise before randomizing patients to clinical trials is widely accepted in the scientific community. Here, we contend that such requirement demands a nuanced and critical interpretation and should not become an obstacle to the conduction and completion of well-conceived clinical trials.
“Do you have equipoise?” The question was simple, yet loaded with challenges. We were being invited to participate in a prospective randomized controlled phase 3 trial testing whether acute endovascular stroke therapy can be beneficial for patients presenting beyond 6 hours from symptom onset (≤6 hours is the currently accepted therapeutic time window for mechanical thrombectomy) when using perfusion brain imaging for selection of candidates. As clinicians, we may have qualms because we are already treating some of these patients with thrombectomy—albeit a minority—in our daily practice. As investigators, we want to participate because we agree with the scientific merit of the study, and we think it has good potential to advance our knowledge and change the standard of care for future patients. So, do we have equipoise? Furthermore, is having equipoise truly an indispensable condition for us to decide whether to participate in this (or any) trial?
To answer this question, we must first understand what we mean when we talk about equipoise. Equipoise is traditionally defined as a state of genuine uncertainty on the relative value of 2 approaches being compared in a trial.1 After its inception, equipoise became rapidly embraced as a necessary condition for randomization in clinical trials. However, the practical application of this ethical concept has proven far from straightforward.
Initially conceived to reflect uncertainty on the part of each individual investigator,1 the concept was subsequently modified by the Canadian Bioethicist Benjamin Freedman2 to instead represent uncertainty within the expert medical community. Freedman …