Read J L, Quinn R J, Berwick D M, Fineberg H V, Weinstein M C
Med Decis Making. 1984;4(3):315-29. doi: 10.1177/0272989X8400400307.
This study compared standard gamble (SG), time trade-off (TTO), and category scaling (CS) methods for assessing preferences among hypothetical outcomes of coronary artery bypass surgery. High correlations among assessment methods, as found in some previous studies, do not assure the absence of systematic differences in rating obtained by different methods. This study used analysis of variance to test for differences among the three assessment methods. Questionnaire responses were obtained from 67 of 109 physicians participating in a postgraduate course on clinical decision making, following a lecture and workshop on utility theory. SG and CS were used to rate multivariate combinations of angina (none, moderate, and severe) and survival (0, 5, and 10 years); and SG, TTO, and CS were used to rate univariate outcomes with angina (none, moderate, and severe) for the remainder of their life expectancy. SG ratings were higher than TTO ratings, which were higher than CS ratings (p less than 0.001 for all comparisons). Multivariate responses revealed a significant interaction between angina and survival dimensions using CS, but not using SG. We conclude that these methods are not interchangeable and that differences between SG and CS require a more complex explanation than differences in attitude toward risk.
本研究比较了标准博弈法（SG）、时间权衡法（TTO）和类别量表法（CS）在评估冠状动脉搭桥手术假设结果偏好方面的应用。正如之前一些研究所发现的，评估方法之间的高度相关性并不能确保不同方法获得的评分不存在系统差异。本研究采用方差分析来检验这三种评估方法之间的差异。在参加临床决策研究生课程的109名医生中，67名医生在听完效用理论讲座和参加相关研讨会后，通过问卷调查获得了他们的反馈。SG和CS用于对心绞痛（无、中度和重度）和生存（0年、5年和10年）的多变量组合进行评分；SG、TTO和CS用于对预期寿命剩余时间内心绞痛（无、中度和重度）的单变量结果进行评分。SG评分高于TTO评分，TTO评分高于CS评分（所有比较的p值均小于0.001）。多变量反应显示，使用CS时，心绞痛和生存维度之间存在显著交互作用，但使用SG时则不存在。我们得出结论，这些方法不可互换，而且SG和CS之间的差异需要比风险态度差异更复杂的解释。
