Fuhrer R
Bull Cancer. 1980;67(4):405-11.
When and how should a physician determine whether to obtain additional clinical information, or whether to start a treatment in view of the information available to him? The concept of the expected value of clinical information can assist the physician in arriving at this decision. Expected value of clinical information is defined as "the difference between the outcome rate (e.g. death rate or survival rate) when the treatment decision must be made without the test information and the outcome rate when the decision can be made contingent upon the test result." We will utilize the decision problem already presented by H.V. Fineberg for patients with chronic progressive liver failure to illustrate this concept, its calculation, and its relationship to factors such as risk associated with the test procedure, sensitivity and specificity of the test, and prevalence of the disease(s) in the population. Usually, "performing a test to gain additional information is worthwhile if at least one decision would change given some test results, and the intrinsic risk of using the test is less than the expected benefit gained from the subsequent change in decision." We will than briefly introduce the subject of sensitivity analysis to illustrate the interrelationship of these different factors upon the decision.
医生应在何时以及如何确定是获取更多临床信息，还是鉴于手头已有的信息开始进行治疗呢？临床信息的期望值这一概念有助于医生做出此决定。临床信息的期望值被定义为“在没有检测信息的情况下做出治疗决策时的结果率（例如死亡率或生存率）与根据检测结果做出决策时的结果率之间的差值”。我们将利用H.V. 芬伯格已经提出的针对慢性进行性肝衰竭患者的决策问题，来说明这一概念、其计算方法以及它与诸如检测程序相关风险、检测的敏感性和特异性以及人群中疾病患病率等因素之间的关系。通常，“如果至少有一个决策会因某些检测结果而改变，并且使用该检测的内在风险小于后续决策改变所带来的预期益处，那么进行检测以获取更多信息就是值得的”。然后我们将简要介绍敏感性分析这一主题，以说明这些不同因素在决策过程中的相互关系。
