CAOP Drug Information and Literature Evaluation 2 — Questions and Answers
Question 1: A study reports a p-value of 0.03. What does this mean?
- There is a 3% chance the drug works
- There is a 3% chance of observing the results by chance if the null hypothesis is true (Correct answer)
- The drug is clinically significant
- The study had a 97% power
Correct answer: There is a 3% chance of observing the results by chance if the null hypothesis is true
A p-value of 0.03 means there is a 3% probability of observing results at least this extreme if the null hypothesis were true.
Question 2: Which bias occurs when sicker patients are more likely to receive the intervention being studied?
- Recall bias
- Allocation bias
- Confounding by indication (Correct answer)
- Detection bias
Correct answer: Confounding by indication
Confounding by indication occurs when the reason for prescribing a drug is also associated with the outcome, distorting the apparent treatment effect.
Question 3: What is the number needed to treat (NNT) if the absolute risk reduction is 5%?
- 5
- 10
- 20 (Correct answer)
- 50
Correct answer: 20
NNT = 1 ÷ ARR = 1 ÷ 0.05 = 20, meaning 20 patients must be treated to prevent one additional adverse event.
Question 4: Which secondary drug information source indexes biomedical literature and helps locate primary studies?
- Micromedex
- Lexicomp
- MEDLINE (PubMed) (Correct answer)
- Martindale: The Complete Drug Reference
Correct answer: MEDLINE (PubMed)
MEDLINE (accessed via PubMed) is a bibliographic database that indexes primary biomedical literature and is classified as a secondary resource.
Question 5: When critically evaluating a clinical trial, which element best assesses internal validity?
- Journal impact factor
- Sample size calculation and randomization method (Correct answer)
- Number of study centers
- Country where the study was conducted
Correct answer: Sample size calculation and randomization method
Proper randomization and an a priori sample size calculation are fundamental to reducing bias and ensuring the study's internal validity.
Question 6: A pharmacist receives a question about a drug not available in the US. Which resource would be MOST useful?
- FDA Orange Book
- Martindale: The Complete Drug Reference (Correct answer)
- US Pharmacopeia
- ASHP Drug Shortages database
Correct answer: Martindale: The Complete Drug Reference
Martindale covers drugs available worldwide, including those not approved in the US, making it the best resource for international drug inquiries.
CAOP Drug Information and Literature Evaluation 2
A study reports a p-value of 0.03.
What does this mean?