Under what conditions is a very sensitive test used?
Correct. You chose {selectedText}.
Incorrect. You chose {selectedText}, but the correct answer is {correctText}.
You need a very sensitive test if:
1. Disease is rare (e.g.: BSE)
2. Early Dx improves prognosis (e.g.: HIV in people)
3. The disease is highly lethal or consequences of missing a case are severe (e.g.: rabies, brucellosis, BSE, screw-worm, FMD, EIA)
Remember that a HIGHLY SENSITIVE test will have very FEW false negatives.
That means if a test is highly sensitive, you can TRUST a NEGATIVE TEST.
This sounds contradictory, but it makes more sense if you review this sensitivity diagram.
Sensitivity=a/(a+c). «a» are true positives. «c» are false negatives.
If sensitivity is HIGH then «c» (FALSE negs) must be small.
Therefore, high sensitivity means you can really trust a NEGATIVE result to be correct.
