Diagnostic Tests OME

Question 1

define precise

Answer 1

arrows have landed close to one another, but not on the bullseye

Question 2

define accurate

Answer 2

arrows aren’t necessarily grouped close to one another, but they center around the bullseye

Question 3

what does accurate and precise look like?

Answer 3

arrows that have landed close to one another around the bullseye

Question 4

sensitivity vs specificity

Answer 4

sensitivity: screenings (ex: Pap smear), won’t miss dx but tend to include false positives
- SN-N-OUT: if the test is negative, then dx is ruled out

specificity: f/u to screenings (ex: colposcopy), very few false positives
- SP-P-IN: if the test is positive, then dx is ruled in

Question 5

PPV

Answer 5

positive predictive value: increased dx prevalence in a population will increase the PPV

Question 6

how is the two-by-two square set up?

Answer 6

top axis = pos dx / neg dx
left axis = test pos / test neg
left row = sensitivity
right row = specificity
top row = PPV
bottom row = NPV

top L box = TP, top R box = FP
bottom L box = FN, bottom R box = TN

equations = true / true + false