SPM – MCQ 52 – Post test probability

You have diagnosed a patient clinically as having SLE and ordered 6 tests. Out of which 4 tests have come positive and 2 are negative. To determine the probability of SLE at this point, you need to know:
a) Prior probability of SLE; sensitivity and specificity of each test
b) Incidence of SLE and predictive value of each test
c) Incidence and prevalence of SLE
d) Relative risk of SLE in this patient

Correct answer : a) Prior probability of SLE; sensitivity and specificity of each test