Help for this question please and have details For the combined ELSI.pdf
0 likes6 views
The document provides a calculation of the positive predictive value for a combined ELSIA-Western Blot blood test for HIV positive status, highlighting the test's high sensitivity (0.999) and specificity (0.9999). It illustrates how to derive the positive predictive value using probabilities of having the disease and test results. The final calculated positive predictive value is approximately 0.9991.
1 of 1
Download to read offline
![Help for this question please and have details For the combined ELSIA-Western blot blood test
for HIV positive status, the sensitivity is about 0.999 and the specificity is about 0.9999.Consider
a high risk group has a positive lest result. Find the positive predictive value of the test.
Solution
Let
D = has disease
T = test positive
Here, note that
P(true positive) = P(D) P(T|D) / P(T)
As
P(T) = P(D) P(T|D) + P(D') P(T|D') = 0.10*0.999 + (1-0.10)*(1-0.9999) = 0.09999
P(true positive) = 0.10*0.999 / 0.09999 = 0.99909991 [ANSWER]](https://image.slidesharecdn.com/helpforthisquestionpleaseandhavedetailsforthecombinedelsi-230706033556-fcf7dd7f/85/Help-for-this-question-please-and-have-details-For-the-combined-ELSI-pdf-1-320.jpg)
More Related Content
More from isenbergwarne4100 (20)
Recently uploaded (20)
Help for this question please and have details For the combined ELSI.pdf
- 1. Help for this question please and have details For the combined ELSIA-Western blot blood test for HIV positive status, the sensitivity is about 0.999 and the specificity is about 0.9999.Consider a high risk group has a positive lest result. Find the positive predictive value of the test. Solution Let D = has disease T = test positive Here, note that P(true positive) = P(D) P(T|D) / P(T) As P(T) = P(D) P(T|D) + P(D') P(T|D') = 0.10*0.999 + (1-0.10)*(1-0.9999) = 0.09999 P(true positive) = 0.10*0.999 / 0.09999 = 0.99909991 [ANSWER]