The Comparative Health Outcome, Policy, and Economics (CHOICE) Institute, Department of Pharmacy and the Departments of Health Services and Economics, University of Washington, Seattle, WA, USA.
Section of Hospital Medicine, Department of Medicine, Harris School of Public Policy Studies and the Department of Economics, The University of Chicago, Chicago, IL, USA.
Med Decis Making. 2018 May;38(4):427-438. doi: 10.1177/0272989X17746988. Epub 2018 Mar 12.
In value of information (VOI) calculations, such as the expected value of perfect information (EVPI), partial perfect information (EVPPI), sample information (EVSI) or implementation (EVIM), the maximum expected value criterion defines the decision making criterion for the adoption of decisions for treatments. However, because decision makers are often risk averse, the uncertainty that accompanies a decision problem may influence adoption decisions.
VOI estimates were studied based on 2 alternate decision making criteria: 1) maximum expected value and 2) 95% credible intervals. These criteria were applied to a probabilistic minimal lifetime model of incident cardiovascular events and mortality among target patients comparing 2 daily doses of aspirin (81 mg and 325 mg). Model parameters were based on literature reviews and data analyses.
Expected life-years under 81 v. 325 mg of aspirin were estimated to be 14.86 (SE, 0.10) and 14.72 (0.31) respectively, with a difference of 0.14 (0.29). The probability that 81 mg was optimal was estimated to be 67%. Under Decision Criterion 1, EVIM and EVPI were about 233-thousand and 411-thousand years, respectively. Under Criterion 2, EVIM was undefined, as there remains ambiguity about what to implement. Consequently, EVPI becomes the entire 644-thousand years. Also, under Criterion 1, EVSI reaches an asymptote at a sample size of 10,000 per arm, with minimal gains in value beyond a 5,000 person per arm trial. With Criterion 2, a sample size of 10,000 per arm or higher is substantially more valuable than lower sample sizes.
Alternative decision criteria for treatment adoption change the VOI. Decision criteria should be justified for VOI analyses. If multiple criteria may be relevant, analysts should complete VOI estimates using multiple criteria.
在信息价值（VOI）计算中，例如期望完美信息价值（EVPI）、部分完美信息价值（EVPPI）、样本信息价值（EVSI）或实施信息价值（EVIM），最大期望价值准则定义了为治疗决策采用决策的决策准则。然而，由于决策者通常是风险厌恶的，伴随决策问题的不确定性可能会影响采用决策。
基于 2 种替代决策准则研究了 VOI 估计值：1）最大期望价值和 2）95%可信区间。这些标准应用于比较 2 种剂量阿司匹林（81mg 和 325mg）的目标患者心血管事件和死亡率的概率最小寿命模型。模型参数基于文献综述和数据分析。
估计每天服用 81 毫克和 325 毫克阿司匹林的预期寿命分别为 14.86（SE，0.10）和 14.72（0.31），相差 0.14（0.29）。估计 81mg 更优的概率为 67%。在决策准则 1 下，EVIM 和 EVPI 分别约为 23.3 万和 41.1 万。在准则 2 下，EVIM 未定义，因为实施什么仍存在歧义。因此，EVPI 成为整个 64.4 万。此外，在准则 1 下，当每个手臂的样本量达到 10000 时，EVSI 达到渐近线，每个手臂超过 5000 人的试验价值增加最小。在准则 2 下，每个手臂 10000 或更高的样本量比低样本量更有价值。
治疗采用的替代决策准则会改变 VOI。应根据 VOI 分析为决策标准提供理由。如果多个标准可能相关，则分析人员应使用多个标准完成 VOI 估计。
