Epidemiology/Biostatistics

Question 1

How do you calculate sensitivity and specificity?

Answer 1

Sensitivity = TP/(TP + FN)
Specificity = TN (TN + FP)

A highly specific test, when positive, rules in a disease (SPIN)
A highly sensitive test, when negative rules out a disease (SNOUT)

Question 2

Calculate odds ratio

Answer 2

AxD/BxC (after filling out 2x2 table)

Question 3

If a positive test result will result in euthanasia, which combination of sensitivity/specificity would you want the test to have?

Answer 3

Highly specific (you do not want false positives)

Question 4

Which infectious disease can cause a false positive on PARR?

Answer 4

Ehrlichia