srk2fd
Forum Junior
Topics: 18
Posts: 39
|
This supposedly comes from a kaplan prac test...see what you think
The standard test to detect an STD has a sensitivity of 90% and a specificity of 70%. If a recent cross-sectional study found that one out of every 10 people has this disease, the positive predictive value is best estimated as:
a - 21%
b - 33%
c - 50%
d - 67%
e - 85%
they say the answer is b
|
| samsoccer7
|
Correct me if i'm wrong:
if you set up a 2x2 chart like this:
TP = 9 FP = 27
FN = 1 TN = 63
That should make sensitivity=90% and specificity=70%, with 10% disease prevalence. So PPV=TP/(TP+FN)=9/36=25%.
What do you guys think?
|
|
| |
| | |
