A population of 1000 people in whom the prevalence of disease XYZ is 50%. ABC screening test was used to screen disease which has specificity and sensitivity of 50 %. What is positive predictive value of screening test ABC.
Total Population = 1000 Prevalence = 50% People have Disease = 500 Not have Disease = 500 Method 1 Test Disease [?] Th [?] A TP ? B FP ? Th C FN ? D TN ? 500 (given) 500 (given) 1000 (given) Test Disease [?] Th [?] A 250 B 250 Th C 250 D 250 Method 2 ( Baye's Theorum)
50%
25%
75%
10%
Screening