Ortendahl Monica, Fries James F
Stanford University School of Medicine, Department of Medicine, Division of Immunology and Rheumatology, Palo Alto, CA, USA.
Med Sci Monit. 2006 Mar;12(3):RA41-5. Epub 2006 Feb 23.
Time-related aspects have attracted an increasing interest in medical decisions. Health promotion often works toward remote goals, and many clinical judgments and decisions include an exchange of costs today for benefits in the future. The concept of diminishing value over time is positive discounting when the benefits occur so far in the future that they seem of little value relative to the immediate cost. If there is a preference to live for the present rather than save for the future, such a preference might not contribute to good health according to a lower discount rate. As discounting is related to risk an analysis of uncertainty is required being an unavoidable condition in health work. Shared decision-making between doctor and patient has increasingly been emphasized, where risk characteristics and time-related aspects should be taken into account to reach a decision based upon mutual agreement. The framework of time and risk for analysis can perform a useful role in clinical judgments and decisions, where framing of different features of risk might diminish discounting and increase compliance to treatment. A summary of valuation factors in medical decision making is presented: (a) long-term decisions are sensitive to discount rates; (b) discount rates vary by domain, by outcome, by individuals and by level of certainty; (c) probability discounting is used if the risk is perceived as controllable; (d) the doctor uses expected value, the patient is risk aversive; (e) asymmetric discounting for patients and doctors gives poor compliance; (f) discount rates are influenced by framing.
与时间相关的因素在医学决策中越来越受到关注。健康促进往往致力于实现远期目标，许多临床判断和决策都涉及到用当下的成本换取未来的收益。当收益在遥远的未来才会出现，以至于相对于当前成本而言显得价值不大时，随着时间推移价值递减的概念就是正向贴现。如果存在更倾向于当下生活而非为未来储蓄的偏好，根据较低的贴现率，这种偏好可能无助于健康。由于贴现与风险相关，因此需要对不确定性进行分析，而这在医疗工作中是不可避免的情况。医生与患者之间的共同决策越来越受到重视，在共同决策时应考虑风险特征和与时间相关的因素，以便基于双方的共识做出决策。时间和风险分析框架在临床判断和决策中可以发挥有益作用，其中对不同风险特征的构建可能会减少贴现并提高对治疗的依从性。本文介绍了医学决策中估值因素的总结：（a）长期决策对贴现率敏感；（b）贴现率因领域、结果、个体和确定性水平而异；（c）如果风险被视为可控，则使用概率贴现；（d）医生使用期望值，患者厌恶风险；（e）患者和医生的非对称贴现会导致依从性差；（f）贴现率受框架影响。
