87. In test for pironoma, a serious disease, a false positive result indicates that people have pironoma when, in fact, they do not; a false negative result indicates that people do not have pironoma when, in fact, they do. To detect pironoma most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.
Which of the following, if true, gives the most support to the recommendation above?
(A) The accepted treatment for pironoma does not have damaging side effects.
(B) The laboratory test that has the lowest proportion of false positive results causes the same minor side effects as do other laboratory tests used to detect pironoma.
(C) In treating pironoma patients, it is essential to begin treatment as early as do possible, since even a week of delay can result in loss of life.
(D) The proportion of inconclusive test results is equal for all laboratory tests used to detect pironoma.
(E) All laboratory tests to detect pironoma have the same proportion of false negeative results.
答案是E
不知道大家是怎么解这道题的 我选的a
这个题我用排除法选的e,可是看了og的解释还是不明白为什么 . If all tests have the same proportion of false negatives, then the most accurate is the one that has the lowest proportion of false positives.
求助大家
既然 所有的test的negatives都是一样的比例,那么positives的比例也都是一样了,怎么找出那个positive的比例最小的来呢?
完了,又短路了
我觉得是这样的:positive即使错了,也只是把没有弄成有;而negative的如果错了的话,就是漏网之鱼,患者有生命危险。
清理上应该倾向于使用positive的测试方法(尽量避免误诊造成的死亡)。但是如果N测试的准确率很高,就可以消除上述的担心。
而 E 所诉,只要用negative的测法,就肯定有误诊。进而支持了使用P测法。
当然隐含的调节是P测法不存在固定错误率的问题,选取其中最优的就是最好的测法。
(E) All laboratory tests to detect pironoma have the same proportion of false negeative results.
请教为什么要强调All呢?
这个题我觉得是这样子解的
根据公式 fp的比例=fp/(fp+fn) 选FP比例最小的(假设条件fn都一样),就是选Fp发生次数最少的。
这里想不明白可以想在 同一杯水里放白糖,放的白糖少,浓度就小。这里 水=fn 质量不变。 白糖=FP.
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