Freedman B
N Engl J Med. 1987 Jul 16;317(3):141-5. doi: 10.1056/NEJM198707163170304.
The ethics of clinical research requires equipoise--a state of genuine uncertainty on the part of the clinical investigator regarding the comparative therapeutic merits of each arm in a trial. Should the investigator discover that one treatment is of superior therapeutic merit, he or she is ethically obliged to offer that treatment. The current understanding of this requirement, which entails that the investigator have no "treatment preference" throughout the course of the trial, presents nearly insuperable obstacles to the ethical commencement or completion of a controlled trial and may also contribute to the termination of trials because of the failure to enroll enough patients. I suggest an alternative concept of equipoise, which would be based on present or imminent controversy in the clinical community over the preferred treatment. According to this concept of "clinical equipoise," the requirement is satisfied if there is genuine uncertainty within the expert medical community--not necessarily on the part of the individual investigator--about the preferred treatment.
临床研究的伦理要求具备 equipoise（均衡）——即临床研究者对于试验中各治疗组相对治疗优势处于真正的不确定状态。若研究者发现某一种治疗具有更优的治疗优势，那么从伦理角度而言，他或她有义务提供该种治疗。对这一要求的当前理解，即要求研究者在整个试验过程中没有“治疗偏好”，给对照试验的伦理启动或完成带来了几乎无法克服的障碍，并且还可能由于未能招募到足够数量的患者而导致试验终止。我提出一种替代的 equipoise 概念，它将基于临床界当前或即将出现的关于首选治疗方法的争议。根据这种“临床均衡”概念，如果在医学专家群体中——不一定是个体研究者——对于首选治疗方法存在真正的不确定性，那么这一要求即得到满足。
