Norman G R, Stratford P, Regehr G
Department of Clinical Epidemiology and Biostatistics, McMaster University of Hamilton, Ontario, Canada.
J Clin Epidemiol. 1997 Aug;50(8):869-79. doi: 10.1016/s0895-4356(97)00097-8.
To examine the relation between responsiveness coefficients derived directly from a calculation of average change resulting from a treatment intervention (Responsiveness-Treatment or RT) and those derived from retrospective analysis of changed and unchanged groups (Responsiveness Retrospective or RR) based on a global measure of change.
Two approaches were used. First, we used simulation methods to examine the analytical relationship between the RT and RR coefficients. We then located eight studies where it was possible to compute both RT and RR coefficients. As anticipated from theoretical arguments, the RR coefficients were larger than the RT coefficients (1.50 versus 0.41, p < .0001). Within study there was no predictable relationship between the two indices. Across studies, the magnitude of the RR coefficient was strongly related to the correlation with the retrospective global scale, and unrelated to the magnitude of the RT coefficient. The simulated curves fit well with the observed data, and substantiated the observation that the relation between RT and RR coefficients is complex and only weakly related to the size of the treatment effect.
Retrospective methods of computing responsiveness yield little information about the ability of an instrument to detect treatment effects, and should not be used as a basis for choice of an instrument for applications to clinical trials.
基于一种整体变化指标，研究直接由治疗干预导致的平均变化计算得出的反应性系数（反应性-治疗或RT）与通过对变化组和未变化组进行回顾性分析得出的反应性系数（反应性回顾性或RR）之间的关系。
采用了两种方法。首先，我们使用模拟方法来研究RT和RR系数之间的分析关系。然后，我们找到了八项能够计算RT和RR系数的研究。正如理论论证所预期的那样，RR系数大于RT系数（1.50对0.41，p <.0001）。在各项研究中，这两个指标之间没有可预测的关系。在所有研究中，RR系数的大小与与回顾性整体量表的相关性密切相关，而与RT系数的大小无关。模拟曲线与观察数据拟合良好，并证实了RT和RR系数之间的关系是复杂的，且与治疗效果的大小仅存在微弱关联这一观察结果。
计算反应性的回顾性方法几乎无法提供关于一种工具检测治疗效果能力的信息，不应将其作为选择应用于临床试验的工具的依据。
