The principle of equipoise in pediatric drug trials

Equipoise is a fundamental ethical principle in the conduct of interventional trials comparing two or more treatment arms. This principle dictates that, at the time of planning and executing such trials, the researchers must have no compelling evidence that one arm is superior to the other arm(s). That means that it is unethical to involve patients in a study where one intervention is convincingly better than the other, as this would mean that a group of patients will receive an inferior option, which may endanger their health. While this principle may be straightforward at the beginning of a trial, there are numerous ways how it may be subsequently disrupted. Presently, most of the literature on equipoise deals with adult patients, with very little experience in children. This paper illustrates the principle of equipoise and the process of defining it. Because the majority of pediatric medications have not been studied adequately and are not labeled for pediatric use, it is often challenging to decide whether equipoise exists for a certain pharmacological treatment. Moreover, the equipoise may dynamically change during the conduct of a study, if new evidence from other studies becomes available.