AANP Research, Evidence-Based Practice, and Biostatistics

Question 1

Which type of evidence sits at the top of the evidence hierarchy for therapy questions?

Accepted Answer

Systematic review of randomized controlled trials

Answer

Systematic reviews and meta-analyses of well-designed RCTs are the highest level of evidence for intervention questions.

Question 2

A screening test with high sensitivity is most useful for which purpose?

Accepted Answer

Ruling out disease when the result is negative

Answer

Highly sensitive tests rarely miss disease, so a negative result helps rule it out (SnNout).

Question 3

A trial reports p = 0.03 with a prespecified alpha of 0.05. What is the correct interpretation?

Accepted Answer

The null hypothesis is rejected

Answer

A p-value below alpha means the result is statistically significant, so the null hypothesis is rejected. It does not give the probability that the hypothesis is true.

Question 4

A drug reduces the event rate from 15% to 10%. What is the number needed to treat?

Accepted Answer

20

Answer

The absolute risk reduction is 5% (0.05), and NNT = 1/ARR = 1/0.05 = 20.

Question 5

Which study design starts with patients who already have a disease and compares them with controls, looking back at prior exposures?

Accepted Answer

Case-control study

Answer

Case-control studies are retrospective, comparing cases with controls to assess past exposures, and they report odds ratios.

AANP - American Association of Nurse Practitioners Practice Test

AANP - American Association of Nurse Practitioners Practice Test

AANP Research, Evidence-Based Practice, and Biostatistics