Bang Heejung, Ni Liyun, Davis Clarence E
Department of Biostatistics, University of North Carolina at Chapel Hill, 137 E. Franklin Street, Chapel Hill, NC 27599, USA.
Control Clin Trials. 2004 Apr;25(2):143-56. doi: 10.1016/j.cct.2003.10.016.
Success of blinding is a fundamental issue in many clinical trials. The validity of a trial may be questioned if this important assumption is violated. Although thousands of ostensibly double-blind trials are conducted annually and investigators acknowledge the importance of blinding, attempts to measure the effectiveness of blinding are rarely discussed. Several published papers proposed ways to evaluate the success of blinding, but none of the methods are commonly used or regarded as standard. This paper investigates a new approach to assess the success of blinding in clinical trials. The blinding index proposed is scaled to an interval of -1 to 1, 1 being complete lack of blinding, 0 being consistent with perfect blinding and -1 indicating opposite guessing which may be related to unblinding. It has the ability to detect a relatively low degree of blinding, response bias and different behaviors in two arms. The proposed method is applied to a clinical trial of cholesterol-lowering medication in a group of elderly people.
设盲的成功是许多临床试验中的一个基本问题。如果这一重要假设被违反，试验的有效性可能会受到质疑。尽管每年进行数千项表面上的双盲试验，且研究人员承认设盲的重要性，但很少有人讨论衡量设盲有效性的尝试。几篇已发表的论文提出了评估设盲成功的方法，但没有一种方法被普遍使用或被视为标准方法。本文研究了一种评估临床试验中设盲成功的新方法。所提出的设盲指数被缩放到 -1 到 1 的区间，1 表示完全没有设盲，0 表示与完美设盲一致，-1 表示相反的猜测，这可能与破盲有关。它有能力检测相对较低程度的设盲、反应偏差以及两组中的不同行为。所提出的方法应用于一组老年人的降胆固醇药物临床试验。
