Departments of Emergency Medicine and Health Policy, George Washington University, Washington, DC, USA.
Acad Emerg Med. 2012 Sep;19(9):E1109-13. doi: 10.1111/j.1553-2712.2012.01432.x.
The mortality benefit for pulmonary embolism (PE) is the difference in mortality between treated and untreated patients. The mortality benefit threshold is the mortality benefit above which testing for a condition should be initiated and below which it should not. To illustrate this concept, the authors developed a decision model to estimate the mortality benefit threshold at several pretest probabilities for low-risk emergency department (ED) patients with possible PE and compare those thresholds with contemporary management of PE in the United States and what is known and not known about treatment benefits with anticoagulation.
The authors built a decision model of a 25-year-old female with suspected PE. Model inputs were obtained from the literature or clinical judgment when data were unavailable. One-way sensitivity analysis was used to derive the mortality benefit threshold at several fixed pretest probabilities, and two-way sensitivity analysis was used to determine drivers of the mortality benefit threshold.
At a 15% pretest probability, the mortality benefit threshold was 3.7%; at 10% it was 5.2%; at 5% it was 9.8%; at 2% it was 23.5%; at 1% it was 46.3%; and at 0.5% it was 92.1%. In two-way sensitivity analyses, D-dimer specificity, CT angiography (CTA)/CT venography (CTV) sensitivity, annual cancer risk, probability of death from renal failure, and probability of major bleeding were major model drivers.
The mortality benefit threshold for initiating PE testing is very high at low pretest probabilities of PE, which should be considered by clinicians in their diagnostic approach to PE in the ED. The mortality benefit threshold is a novel way of exploring the benefits and risks of ED-based testing, particularly in situations like PE where testing (i.e., CT use) carries real risks and the benefits of treatment are uncertain.
肺栓塞（PE）的死亡率获益是指治疗组与未治疗组之间的死亡率差异。死亡率获益阈值是指高于该值时应启动针对某种疾病的检测，而低于该值时则不应启动。为了说明这一概念，作者开发了一个决策模型，以估计在几种低风险急诊（ED）疑似 PE 患者的术前概率下的死亡率获益阈值，并将这些阈值与美国当代 PE 管理进行比较，以及抗凝治疗的获益和未知情况进行比较。
作者建立了一个 25 岁女性疑似 PE 的决策模型。模型输入来自文献或临床判断，当数据不可用时。作者采用单因素敏感性分析得出了在几个固定术前概率下的死亡率获益阈值，并采用双因素敏感性分析确定了死亡率获益阈值的驱动因素。
在 15%的术前概率下，死亡率获益阈值为 3.7%；在 10%时为 5.2%；在 5%时为 9.8%；在 2%时为 23.5%；在 1%时为 46.3%；在 0.5%时为 92.1%。在双因素敏感性分析中，D-二聚体特异性、CT 血管造影（CTA）/CTV 敏感性、年癌症风险、肾衰竭死亡率和大出血概率是模型的主要驱动因素。
在低术前 PE 概率下，启动 PE 检测的死亡率获益阈值非常高，这应引起临床医生在 ED 诊断 PE 时的重视。死亡率获益阈值是一种探索 ED 检测的获益和风险的新方法，特别是在像 PE 这样的情况下，检测（即 CT 使用）存在真实风险，而治疗的获益不确定。
