Verhoef L C, de Haan A F, van Daal W A
Institute of Radiotherapy, University of Nijmegen, The Netherlands.
Med Decis Making. 1994 Apr-Jun;14(2):194-200. doi: 10.1177/0272989X9401400213.
According to prospect theory, risk attitude changes depending on whether a prospect is perceived as a gain or a loss relative to a reference or aspiration level. To investigate risk attitude with respect to years of life, the authors elicited utilities at two occasions by the certainty equivalent method from 30 women from the general population. The respondents gave certainty equivalents to gambles with years of life. The gambles were two-outcome gambles with equal probabilities to experience each outcome. A shift from a risk-seeking towards a risk-averse attitude was observed with increasing expected value of the gambles. For each individual, the averaged responses over the two replications were fitted with an s-shaped logistic curve that showed an excellent fit (r2 > or = 0.97) for all respondents. The aspiration level of survival can be derived from this function and was negatively correlated with age (r = -0.43, p < 0.025). The data are consistent with prospect theory and may explain why patients opt for risky treatments, since most of the respondents were risk-seeking in the short term.
根据前景理论，风险态度会因前景被视为相对于参考或期望水平的收益还是损失而发生变化。为了研究与寿命相关的风险态度，作者通过确定性等价方法在两个时间点从30名普通女性中获取了效用值。受访者给出了与寿命相关的赌博的确定性等价物。这些赌博是具有两种结果且每种结果出现概率相等的双结果赌博。随着赌博期望值的增加，观察到了从风险寻求态度向风险厌恶态度的转变。对于每个个体，两次重复测量的平均反应通过一条S形逻辑曲线进行拟合，该曲线对所有受访者都显示出极佳的拟合度（r2≥0.97）。生存期望水平可以从该函数中推导出来，并且与年龄呈负相关（r = -0.43，p < 0.025）。这些数据与前景理论一致，并且可能解释了为什么患者会选择有风险的治疗方法，因为大多数受访者在短期内是风险寻求型的。
