Mhaskar Rahul, B Bercu Barry, Djulbegovic Benjamin
Clinical Translational Science Institute, Center for Evidence-based Medicine and Health Outcomes Research, Tampa, FLorida, USA ; Department of Internal Medicine, Division of Evidence-based Medicine and Health Outcomes Research University of South Florida, Tampa, FLorida, USA.
Acta Inform Med. 2013;21(3):156-9. doi: 10.5455/aim.2013.21.156-159.
The conduct of a randomized controlled trial (RCT) is deemed ethical only if we are in state of "equipoise" as to which treatment would be most beneficial for the patients. Individual equipoise applies to an individual clinician or a member of ethical, institutional review board (IRB), whilst collective equipoise refers to the profession as a whole. It is argued that physicians are not bound by the equipoise but their actions are directed by the confines of the expert opinion. Experts can agree or disagree in various proportions on the merit of a given treatment. Hence, the collective equipoise will be often incomplete. In turn, the opinions of content expert in the field of the proposed trial influence the IRB members' decision regarding trial approval.
We conducted a survey of IRB members at University of South Florida and the IRB members attending the bioethics conference organized in Clearwater, Florida, USA. The survey was made available as hard copy (paper based) and included six hypothetical scenarios outlining clinical trials targeted at measuring the collective equipoise. We defined the collective equipoise as the situation when survey participants were equally split (50:50) in their decision regarding whether a proposed clinical trial would be ethical to conduct. The opinion of 100 experts in the field expressed as proportion of experts favoring treatment A vs. B in each of the five scenarios was made available to the participants.
The response rate of our survey was 33% (71/218). Fifty percent of the IRB members would approve an RCT addressing the efficacy of two drugs for the management of headache even if 80% of experts favor one treatment over another (median: 80%; third quartile: 80%). Similarly, half of participating IRB members would approve the study when the median distribution of equipoise among experts was 70% (70 in favor of treatment A vs. 30 in favor of treatment B) for treatment of leukemia, 60% for treatment of geriatric patients and 70% for treatment of newborns. Half of IRB members would approve the study when the median distribution of equipoise among experts was 70% for treatment for leukemia in dogs and 85% for leukemia in rats (and 25% of IRB members would approve such a study even if 100% of experts favors one treatment over another). None of the demographic features of respondents affected collective equipoise.
This is the first study assessing collective equipoise among ethical committee/IRB members. Our study findings show that IRB members perceived that conduct of a trial enrolling humans is unethical when the equipoise level is beyond 80% (80:20 distribution of uncertainty). IRB members require a higher level of equipoise when it comes to testing a new drug in humans than in animals. A relatively high level of equipoise is needed for IRB members to be comfortable to approve trials involving life-threatening situations, children and elderly patients.
只有当我们对于哪种治疗方法对患者最有益处于“ equipoise”状态时,随机对照试验(RCT)的开展才被视为符合伦理道德。个体equipoise适用于个体临床医生或伦理机构审查委员会(IRB)的成员,而集体equipoise则指整个专业领域。有人认为医生不受equipoise的约束,而是受专家意见的限制来指导其行动。专家们对于某种特定治疗方法的优点可能会有不同程度的赞同或反对。因此,集体equipoise往往是不完整的。反过来,拟开展试验领域的内容专家的意见会影响IRB成员关于试验批准的决定。
我们对南佛罗里达大学的IRB成员以及参加在美国佛罗里达州克利尔沃特举办的生物伦理会议的IRB成员进行了一项调查。该调查以纸质版形式提供,包含六个假设情景,概述了旨在衡量集体equipoise的临床试验。我们将集体equipoise定义为调查参与者在关于拟开展的临床试验是否符合伦理道德的决定上意见平分(50:50)的情况。向参与者提供了100位该领域专家在五个情景中对治疗A与治疗B的支持比例意见。
我们的调查回复率为33%(71/218)。即使80%的专家更倾向于一种治疗方法而非另一种,仍有50%的IRB成员会批准一项针对两种治疗头痛药物疗效的RCT(中位数:80%;第三四分位数:80%)。同样,当专家中equipoise的中位数分布为白血病治疗70%(70人支持治疗A,30人支持治疗B)、老年患者治疗60%、新生儿治疗70%时,一半的参与IRB成员会批准该研究。当专家中equipoise的中位数分布为犬白血病治疗70%、大鼠白血病治疗85%时,一半的IRB成员会批准该研究(并且即使100%的专家更倾向于一种治疗方法而非另一种,仍有25%的IRB成员会批准这样的研究)。受访者的任何人口统计学特征均未影响集体equipoise。
这是第一项评估伦理委员会/IRB成员之间集体equipoise的研究。我们的研究结果表明,当equipoise水平超过80%(不确定性分布为80:20)时,IRB成员认为开展涉及人类的试验是不符合伦理道德的。与在动物身上测试新药相比,如果要在人类身上测试新药,IRB成员需要更高水平的equipoise。IRB成员在批准涉及危及生命情况、儿童和老年患者的试验时,需要相对较高水平的equipoise才会感到安心。