Miller and Brody argue that the notion of clinical equipoise is fundamentally misguided. The ethics of therapy and the ethics of research are two distinct enterprises that are governed by different norms. They state, “The doctrine of clinical equipoise is intended to act as a bridge between therapy and research, allegedly making it possible to conduct RCTs without sacrificing the therapeutic obligation of physicians to provide treatment according to a scientifically validated standard of care. This constitutes therapeutic misconception concerning the ethics of clinical trials, analogous to the tendency of patient volunteers to confuse treatment in the context of RCTs with routine medical care.”  Equipoise, they argue, only makes sense as a normative assumption for clinical trials if one assumes that researchers have therapeutic obligations to their research participants. Further criticisms of clinical equipoise have been leveled by Robert Veatch  and by Peter Ubel and Robert Silbergleit. 
early 13c., "apparatus for weighing," from Old French balance (12c.) "balance, scales for weighing," also in the figurative sense; from Medieval Latin bilancia , from Late Latin bilanx , from Latin (libra) bilanx "(scale) having two pans," possibly from Latin bis "twice" + lanx "dish, plate, scale of a balance." The accounting sense is from 1580s; the meaning "general harmony between parts" is from 1732; sense of "physical equipoise" is from 1660s. Balance of power in the geopolitical sense is from 1701. Many figurative uses are from Middle English image of the scales in the hands of personified Justice, Fortune, Fate, etc.; . hang in the balance (late 14c.).