MacKeigan Linda D, Gafni Amiram, O'Brien Bernie J
Faculty of Pharmacy, University of Toronto, Toronto, Canada.
Health Econ. 2003 Feb;12(2):165-9. doi: 10.1002/hec.718.
Quality-adjusted life-years (QALYs) calculated from time tradeoff (TTO) based preferences have a time preference component. To impose a conventional discount rate on these implicitly discounted QALYs introduces some degree of double discounting. The purpose of this study was to determine the magnitude of the double discounting effect and the effectiveness of a suggested method for avoiding double discounting in a TTO-based QALY model. Our analysis used holistic and composite preference scores obtained with the TTO technique in a prior study of four hypothetical treatment paths in type 2 diabetes. Discounted composite preference scores were significantly discrepant from holistic preference scores. Adjusting TTO-based quality weights prior to external discounting reduced the discrepancy only slightly. Since time preference effects may vary with health state context, the double discounting effect needs further investigation.
从基于时间权衡（TTO）的偏好计算得出的质量调整生命年（QALYs）具有时间偏好成分。对这些隐含贴现的QALYs施加传统贴现率会引入一定程度的双重贴现。本研究的目的是确定双重贴现效应的大小以及一种在基于TTO的QALY模型中避免双重贴现的建议方法的有效性。我们的分析使用了在先前一项关于2型糖尿病四种假设治疗路径的研究中通过TTO技术获得的整体和综合偏好分数。贴现后的综合偏好分数与整体偏好分数存在显著差异。在外部贴现之前调整基于TTO的质量权重只能稍微减少差异。由于时间偏好效应可能因健康状态背景而异，双重贴现效应需要进一步研究。
