Blader Joseph C
Department of Psychiatry and Behavioral Science, Stony Brook State University of New York, Stony Brook, NY 11794-8790, USA.
Contemp Clin Trials. 2005 Jun;26(3):290-9. doi: 10.1016/j.cct.2005.01.003. Epub 2005 Mar 3.
Subjects in controlled clinical trials obtain experience with study-provided treatment that could inform their further therapy by awareness of the efficacy or inefficacy of the study treatment they received. However, patients in blinded trials typically do not learn right after their participation what treatment they actually received during the study, even though it is possible to do so while maintaining the necessary blinding of investigators. Keeping investigators and subjects blind to treatment assignment throughout a trial is a key element of clinical research methodology, but the value of keeping participants and their medical providers blinded after participation is less certain and may pose risks that include delay in the receipt of efficacious care, exacerbation of symptoms, or prolonged exposure to superfluous or toxic treatment. The significance of these risks is likely to vary with the specific disease and the time course of its response to available therapies. Currently, it seems appropriate for investigators a) to evaluate the risks of keeping subjects blind after participation, b) to justify doing so in relation to serious, identifiable risks to the study's validity and apprise prospective subjects clearly that information about their response to specific treatment during the trial will not be available to guide their post-study care, and c) to consider methods for debriefing subjects before their resumption of open treatment that preserve the integrity of investigator blinding. In the long-run, research on the impact that keeping subjects uninformed about study treatment has on post-study patient outcomes and on study integrity can foster the development of procedures that optimally balance both.
在对照临床试验中，受试者会体验研究提供的治疗，通过了解所接受研究治疗的疗效或无效性，这些经验可为其后续治疗提供参考。然而，在盲法试验中，患者参与试验后通常无法立即得知自己在研究期间实际接受的治疗，尽管在保持研究者必要盲态的同时告知患者是可行的。在整个试验过程中让研究者和受试者对治疗分配保持盲态是临床研究方法的关键要素，但在试验结束后仍让参与者及其医疗服务提供者保持盲态的价值则不太确定，且可能带来风险，包括延迟接受有效治疗、症状加重或长期暴露于多余或有毒的治疗。这些风险的重要性可能因具体疾病及其对现有治疗反应的时间进程而异。目前，研究者似乎应：a)评估让受试者在参与试验后保持盲态的风险；b)就保持盲态对研究有效性的严重、可识别风险进行说明，并明确告知潜在受试者，在试验期间关于他们对特定治疗反应的信息将无法用于指导其研究后的护理；c)考虑在受试者恢复开放治疗前进行汇报的方法，同时保持研究者盲态的完整性。从长远来看，研究让受试者对研究治疗不知情对研究后患者结局和研究完整性的影响，有助于开发出能最佳平衡两者的程序。
