Johannesson M
Stockholm School of Economics.
Int J Technol Assess Health Care. 1995 Winter;11(1):40-8. doi: 10.1017/s0266462300005249.
This paper investigates the theoretical properties of healthy-years equivalents (HYEs) and quality-adjusted life-years (QALYs). A distinction is made between ex ante HYEs (EA-HYEs) and expected HYEs (EXP-HYEs) and between risk-neutral quality-adjusted life-years (RN-QALYs) and risk-adjusted quality adjusted life-years (RA-QALYs). In the case of certainty, HYEs always rank health profiles according to individual preferences, whereas QALYs only rank health profiles according to individual preferences if constant proportional trade-off holds for all health states and if additive independence of quality in different periods holds. In the case of uncertainty, EA-HYEs always rank risky health profiles the same way as expected utility. The assumptions needed for the other measures to rank risky health profiles the same way as expected utility are: risk neutrality with respect to healthy time for EXP-HYEs; risk neutrality with respect to time in all health states and additive independence of quality in different periods for RN-HYEs; and constant proportional risk posture with respect to time in all health states and additive independence of quality in different periods for RA-QALYs.
本文研究了健康等效年（HYEs）和质量调整生命年（QALYs）的理论特性。区分了事前健康等效年（EA-HYEs）和预期健康等效年（EXP-HYEs），以及风险中性质量调整生命年（RN-QALYs）和风险调整质量调整生命年（RA-QALYs）。在确定性情况下，健康等效年总是根据个人偏好对健康状况进行排序，而质量调整生命年只有在所有健康状态下都保持恒定比例权衡且不同时期质量具有加性独立性时，才会根据个人偏好对健康状况进行排序。在不确定性情况下，事前健康等效年对有风险的健康状况的排序方式总是与预期效用相同。其他指标要与预期效用以相同方式对有风险的健康状况进行排序所需的假设是：对于预期健康等效年，在健康时间方面风险中性；对于风险中性质量调整生命年，在所有健康状态下对时间风险中性且不同时期质量具有加性独立性；对于风险调整质量调整生命年，在所有健康状态下对时间具有恒定比例风险态势且不同时期质量具有加性独立性。
