Franic Duska M, Pathak Dev S
College of Pharmacy, University of Georgia, Department of Clinical and Administrative Sciences, Athens 30602-2354, USA.
Int J Technol Assess Health Care. 2003 Spring;19(2):347-61. doi: 10.1017/s026646230300031x.
Most studies typically measure health preferences excluding health states perceived as worse than death. The objective of this study is to test the impact of including (versus excluding) health states perceived to be worse than death on utility measurement using standard gamble (SG) and visual analogue scale (VAS) methods.
By means of a cross-sectional descriptive study design, women were asked to rate the utility of three hypothetical breast cancer health states: cure, treatment, and recurrence (n=119). Preference weights were estimated, allowing for negative utilities with death (perfect health) scaled at zero (1.0).
Unpaired t-test analysis showed significantly greater change in SG and VAS weights for individuals perceiving cancer recurrence as worse than death than those perceiving death as least desirable state. Excluding negative utilities from the study resulted in significantly smaller changes in utility. Study results show that preference elicitation methods can be successfully adapted to acquire negative utilities.
Changes in utility were greater when negative preferences were permitted. Addressing negative preference scores could significantly affect quality adjusted life year estimates in economic analyses.
大多数研究通常在测量健康偏好时排除那些被认为比死亡更糟糕的健康状态。本研究的目的是使用标准博弈法（SG）和视觉模拟量表法（VAS），测试纳入（相对于排除）被认为比死亡更糟糕的健康状态对效用测量的影响。
采用横断面描述性研究设计，让女性对三种假设的乳腺癌健康状态进行效用评分：治愈、治疗和复发（n = 119）。估计偏好权重，将死亡（完美健康）的负效用设定为零（1.0）。
非配对t检验分析显示，与那些将死亡视为最不理想状态的人相比，认为癌症复发比死亡更糟糕的个体在SG和VAS权重上的变化显著更大。在研究中排除负效用会导致效用变化显著更小。研究结果表明，偏好诱导方法可以成功地用于获取负效用。
当允许负偏好时，效用变化更大。在经济分析中，处理负偏好分数可能会显著影响质量调整生命年的估计。
