172. There is a great deal of geographical variation in the frequency of many surgical procedures—up to tenfold variation per hundred thousand between different areas in the numbers of hysterectomies, prostatectomies, and tonsillectomies. To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following? (A) A local board of review at each hospital examines the records of every operation to determine whether the surgical procedure was necessary. (B) The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered. (C) There are several categories of surgical procedure (other than hysterectomies, prostatectomies, and tonsillectomies) that are often performed unnecessarily. (D) For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or whether alternative treatment would have succeeded. (E) With respect to how often they are performed unnecessarily, hysterectomies, prostatectomies, and tonsillectomies are representative of surgical procedures in general. 请问这道题目怎么理解啊,怎样的思路啊?感觉题目怪怪的,答案也不太理解 the key is B作者: ghfgss231 时间: 2006-4-12 07:24
排除他因作者: daoying 时间: 2006-4-17 13:06
Actually, this is a problem of assumption.As carefield said, the choice B rule out a posibility that it is disease-relatied factors rather than geographical variation that cause unnecessary surgical procedures and thus is an additional premise for the establishment of the conslusion.作者: hopr999 时间: 2006-4-18 20:12
