a***e
发帖数: 1627 | 1 In diagnostic testing, we define
D as disease present Dc as disease absent
+ as test is positive - as test is negative
P(D) = probability of disease = prevalence
The precision of the test is measured by two quantities:
P(+|D) = sensitivity
P(-|Dc) = specificity
Suppose that the sensitivity = .95 and the specificity = .90.
a)Assume that the prevalence of the disease in the population is .04.
Given that the test is positive what is the probability that the
disease is truly present, that is, calculate P(D|+).
怎么算搞不定,请教大家,谢谢啦 | k*******a
发帖数: 772 | 2 P(+|D)*P(D)/[P(+|D)*P(D)+P(+|Dc)*P(Dc)]
里面的量都是已知的
P(+|Dc)=1-P(-|Dc) | a***e
发帖数: 1627 | 3 谢谢 做好了 发现自己看错题了 真是只猪嘿嘿
【在 k*******a 的大作中提到】
: P(+|D)*P(D)/[P(+|D)*P(D)+P(+|Dc)*P(Dc)]
: 里面的量都是已知的
: P(+|Dc)=1-P(-|Dc)
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