CMAS Research Methods & Evidence-Based Practice 2 — Questions and Answers
Question 1: Which study design is considered the gold standard for establishing causality in clinical research?
- Cross-sectional study
- Randomized controlled trial (RCT) (Correct answer)
- Case-control study
- Cohort study
Correct answer: Randomized controlled trial (RCT)
RCTs use random assignment to minimize bias, making them the gold standard for establishing cause-and-effect relationships.
Question 2: In evidence-based practice, what does the acronym PICO stand for?
- Patient, Intervention, Comparison, Outcome (Correct answer)
- Population, Intervention, Control, Objective
- Problem, Index, Criteria, Observation
- Patient, Index, Comparison, Objective
Correct answer: Patient, Intervention, Comparison, Outcome
PICO stands for Patient/Population, Intervention, Comparison, and Outcome, and is used to frame clinical research questions.
Question 3: A medical researcher wants to study the long-term effects of a new medication by following a group of patients over 10 years. Which study design is most appropriate?
- Case study
- Cross-sectional study
- Prospective cohort study (Correct answer)
- Retrospective case-control study
Correct answer: Prospective cohort study
A prospective cohort study follows participants forward in time, making it ideal for studying long-term outcomes of exposures or treatments.
Question 4: What is the primary purpose of blinding in a clinical trial?
- To reduce study costs
- To increase sample size
- To minimize bias from participant or researcher expectations (Correct answer)
- To ensure equal group sizes
Correct answer: To minimize bias from participant or researcher expectations
Blinding prevents participants and/or researchers from knowing treatment assignments, reducing performance and detection bias.
Question 5: Which level of evidence is typically assigned to expert opinion and case reports?
- Level I
- Level II
- Level IV
- Level V (Correct answer)
Correct answer: Level V
Expert opinions and case reports sit at the lowest level (Level V) of the evidence hierarchy due to their susceptibility to bias.
Question 6: A p-value of 0.03 in a research study indicates:
- There is a 3% chance the treatment is effective
- There is a 97% probability the null hypothesis is true
- There is a 3% probability the observed result occurred by chance alone (Correct answer)
- The study has a 3% margin of error
Correct answer: There is a 3% probability the observed result occurred by chance alone
A p-value of 0.03 means there is only a 3% probability of obtaining the observed result if the null hypothesis were true.
Question 7: Which database is considered the primary source for peer-reviewed biomedical literature searches?
- CINAHL
- EMBASE
- PubMed/MEDLINE (Correct answer)
- Cochrane Library
Correct answer: PubMed/MEDLINE
PubMed/MEDLINE, maintained by the National Library of Medicine, is the primary database for biomedical and life sciences literature.
CMAS Research Methods & Evidence-Based Practice 2
Which study design is considered the gold standard for establishing causality in clinical research?