在某种意义上,流行病学是一门研究疾病群体现象的方法学。流行病的任务包括病因的探讨、防制措施的考核等等,无不是在分析变量(Variable)与事件(Event)的因果联系,提出论证要依赖于流行病学方法,反之,评价这些论证也离不开流行病学方法。早在廿世纪以前,就有不少应用流行病学而阐明了疾病病因的经典事例,例如Pott与阴囊癌、Snow J与霍乱、Lind J与坏血病、Goldberger与糙皮疾等。本世纪五十年代末,震惊世界的“反应停事件”(Thalidomide致新生儿四肢畸形)是应用流行病学 In a sense, epidemiology is a methodology for studying the phenomenon of disease groups. The tasks of epidemics include the etiological investigation, the examination of prevention measures, and so on, all of which are not in analyzing the causal connection between variables and events, and arguing that the demonstration depends on epidemiological methods. On the contrary, Can not do without epidemiological methods. As early as the twentieth century, there are many classic examples of epidemiological applications that elucidate the etiology of the disease, such as Pott and scrotum, Snow J and cholera, Lind J and scurvy, Goldberger and Kelp. The late 50s of this century, shock the world’s “reaction stop event” (Thalidomide caused neonatal limb deformities) is the application of epidemiology