Helgason C M, Jobe T H
University of Illinois College of Medicine, Chicago, Ill. 60612, USA.
Neuroepidemiology. 1999;18(2):64-74. doi: 10.1159/000069409.
In evidence-based medicine, stroke subtype is diagnosed after a sequential search for etiology; the first positive test result of significant severity rounds off to one overwhelming cause. Degree of severity, interaction among variables, and concomitant variable conditions are not considered in defining the cause of stroke. Yet, thrombus formation, and possibly vascular rupture, is an interactive process involving the vascular wall, flow properties of the blood and blood constituents; this process occurs in homeostasis and pathology. Evidence-based medicine ignores this process and instead studies stroke using crisp 'all or none' classification where subtypes are distinct and interactively relate only to outcome. As a result, scientific inquiry is focused on prediction for the collective of patients. The statistical approach of evidence-based medicine is founded on probability theory, itself rooted in classical set theory where elementhood is all (1) or none (0), and opposites interact only to form the null set. Fuzzy set theory, where set membership is to degree [0, 1], encompasses classical set theory, allows for an interactive process between variables, and therefore becomes the measure of complexity. Fuzzy set theory can change the scientific method of evidence-based medicine.
在循证医学中，中风亚型是在对病因进行逐一排查后确诊的；具有显著严重性的首个阳性检测结果归结为一个主要病因。在确定中风病因时，未考虑严重程度、变量之间的相互作用以及伴随的变量情况。然而，血栓形成以及可能的血管破裂是一个涉及血管壁、血液流动特性和血液成分的相互作用过程；这个过程发生在稳态和病理状态中。循证医学忽略了这个过程，而是使用清晰的“全有或全无”分类法来研究中风，其中亚型是截然不同的，并且仅与结果存在交互关系。因此，科学探究聚焦于对患者群体的预测。循证医学的统计方法建立在概率论基础之上，而概率论本身又植根于经典集合论，在经典集合论中，元素属于集合的情况要么是全部（1），要么是没有（0），且对立情况之间相互作用只会形成空集。模糊集合论中，集合成员资格是程度性的[0, 1]，它包含了经典集合论，允许变量之间存在相互作用过程，因此成为衡量复杂性的方法。模糊集合论可以改变循证医学的科学方法。
