Collaborative Research: Adding Extrinsic Goals to the QALY Model (with Alan Schwartz)

评价卫生质量的方法是医疗成本效益分析的核心。 其中最重要的方法是质量调整生命年（QALY），即患者的生命长度与健康质量成正比。 然而，许多研究已经证明，测量的Q值与患者当前健康状况之间的相关性充其量是适度的。 此外，人们知道，当剩余寿命较长时，个人可能会用寿命来换取健康质量的改善，但当剩余寿命较短时则不会;健康质量差的人可能更愿意只活到实现重要的生命里程碑，而不再活下去。 目前的QALY模型并不适应这些现象，为了解决这些问题，研究者将研究将生活目标纳入健康偏好模型的方法。 QALY模型已经解决了“持续的目标”，这些目标的影响与寿命成正比，例如最大限度地减少慢性疼痛或保持身体活动能力。 其他目标，如完成一个重要的项目或看到一个孩子从大学毕业，被称为“外在目标”，是有质的不同;他们的成就有影响独立于寿命的长短。 这些问题没有被QALO解决。 研究者已经将QALY模型推广到包括持续目标和外在目标。 在这个模型的指导下，研究人员将进行实证研究，以确定对公众和医疗患者来说重要的外在目标的特征。 他们将进行理论研究，调查外在目标的潜在偏好模型，包括多个外在目标的方法，以及增加外在目标时对已发表的医疗决策分析的影响。 他们将确定外在目标是否有助于解释QALY模型所禁止的合理行为，或者比QALY更好地将测量的偏好与当前健康状况相关联。 尽管有其局限性，QALY模型已成为医疗成本效益分析中患者偏好建模的标准。 研究者的外在目标模型构成了对这一标准的基本的和原始的扩充。 它有可能通过大幅扩大这些分析中包括的患者和社区偏好的类型来造福社会。

Methods for evaluating health quality are central to medical cost-effectiveness analyses. The most important such method is the quality-adjusted life year (or QALY), in which a patient's length of life is given weight proportional to quality of health. However, numerous studies have demonstrated that the correlation between measured QALYs and a patient's current health is at best modest. Moreover, it is known that individuals may trade lifetime for improved health quality when remaining lifetime is long, but not when it is short; and that those with poor health quality may prefer to survive only until important life milestones are achieved and no longer. Current QALY models do not accomodate these sorts of phenomena.To address these concerns, the investigators will examine methods for incorporating life goals into health preference models. The QALY model already addresses "ongoing goals" that have impact proportional to length of life, such as minimizing chronic pain or maintaining physical mobility. Other goals, termed "extrinsic goals," such as completing an important project or seeing a child graduate from college, are qualitatively different; their achievement has impact independent of length of life. These are not addressed by QALYs. The investigators have generalized the QALY model to incorporate both ongoing goals and extrinsic goals. Guided by this model, the investigators will conduct empirical studies to characterize the kinds of extrinsic goals that are important for the general public and medical patients. They will conduct theoretical studies investigating potential preference models for extrinsic goals, methods for including multiple extrinsic goals, and impacts on published medical decision analyses when extrinsic goals are added. They will determine if extrinsic goals can help explain plausible behavior forbidden by the QALY model or yield better correlation of measured preferences with current health than does QALY. Despite its limitations, the QALY model has become the standard for modeling patient preferences in medical cost-effectiveness analyses. The investigators' extrinsic-goal model constitutes a fundamental and original augmentation of this standard. It has the potential to benefit society by substantially broadening the types of patient and community preferences included in these analyses.