quiz 5

Question 1

You are investigating the evidence involved in the diagnosis of infectious mononucleosis. You find the following data:
Finding LR+ LR-
splenomegaly
7.0 0.94
any cervical adenopathy 2.1 0.22
posterior cervical adenopathy
3.1 0.69
headache
1.3 0.73

Which of the following combinations of findings should you avoid applying (i.e. you should apply evidence from only one of the findings)?
Question 1 Answer

a.
Splenomegaly and posterior cervical adenopathy

b.
Splenomegaly and headache

c.
Splenomegaly and any cervical adenopathy

d.
Any cervical adenopathy and posterior cervical adenopathy

Answer 1

d.
Any cervical adenopathy and posterior cervical adenopathy

Question 2

You are reading an article about the diagnosis of infectious mononucleosis and see the following likelihood ratios:
7.0
0.94
0.3
0.03
Which LR represents the minimum information you would need to move your estimate of the probability from approximately 10% to less than 1%?

a.
7.0

b.
0.94

c.
0.03

d.
0.3

Answer 2

c.
0.03

Question 3

With which pretest probability would your estimate of the probability change the most If you applied evidence with an LR of 5?
Question 3 Answer

a.
50%

b.
1%

c.
5%

d.
95%

Answer 3

a.
50%

Question 4

A naturopathic doctor claims that the treatment they recommend for CIN 1 (a condition where there are slightly abnormal cervical cells) is effective. They say that 75% of the women they treat who have CIN 1 find that their condition resolves. Before deciding how persuasive this evidence should be, what further piece of information would be most important to consider?
Question 4 Answer

a.
How often women find that their CIN 1 resolves without this intervention

b.
What CIN 1 stands for and what the naturopathic doctor means by “resolves”

c.
Whether they are treating typical or atypical cases of CIN 1, or if they are in fact treating CIN 2

d.
Whether the women this naturopathic doctor is treating are claiming they have improved when in fact they haven’t

Answer 4

a.
How often women find that their CIN 1 resolves without this intervention

Question 5

You are looking for diagnostic evidence in the literature and are having difficulty finding likelihood ratios. What should you look for in order to be able to calculate likelihood ratios?
Question 5 Answer

a.
Diagnostic odds ratios

b.
Sensitivity and specificity

c.
Positive predictive value (PPV) and negative predictive value (NPV)

d.
Pretest probability and post-test probability

Answer 5

b.
Sensitivity and specificity