[問題]OG(VR) 53

[oneseven]

53
There is a great deal of geographical variation in the frequency of many surgical procedures -- up to tenfold variation per hundred thousand people among 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 wach hospital examines the records of every operation to determine whether the surgical procedure was necessary.
(B) The variation is unrelated to factors ( other than teh surgical procedures themselves) that influence the incidence of diseases for which surgical 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.

Answer: B
有看了書上的解說 但還是不明白為什麼
希望大家可以解釋一下 謝謝

[阿琪]

參考看看前輩們的討論串囉！
重點在排除其它因素~

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