There is a great deal of geographical variation in the frequency of many surgical procedures—up to tenfold variation per hundred thousand people 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.作者: regards 时间: 2012-9-15 15:57
继续求作者: regards 时间: 2012-9-15 20:57 作者: kennyz1120 时间: 2012-9-16 12:05
题：许多手术的施行频率因地区而异，不同地区进行H,P,T（不同手术的名称）的比例差异很大 问：为了支持“是因为不必要的手术而导致差异大”这种说法，以下哪个观点需成立？
