Pre- and post- test odds and probability Flashcards
proportion of people with the target disorder in the population at risk at a specific time or time interval
Pre-test probability
point prevalence vs period prevalence
proportion of patients with that particular test result who have the target disorder
Post-test probability
post test odds / (1 + post-test odds) =?
Post test probability
odds that the patient has the target disorder before the test is carried out
Pre-test odds= pre-test probability / (1 - pre-test probability)
odds that the patient has the target disorder after the test is carried out
Post-test odds = pre-test odds x likelihood ratio*
*where the likelihood ratio for a positive test result = sensitivity / (1 - specificity)