DO Diagnostic Reasoning and Evidence-Based Medicine 2 — Questions and Answers
Question 1: Which approach to clinical decision-making integrates the best available research evidence with clinical expertise and patient values?
- Evidence-based medicine (EBM) (Correct answer)
- Eminence-based medicine
- Intuitive diagnosis
- Algorithmic medicine
Correct answer: Evidence-based medicine (EBM)
EBM as defined by Sackett integrates best research evidence, clinical expertise, and patient preferences and values into clinical decision-making.
Question 2: The positive predictive value (PPV) of a test increases as:
- Disease prevalence in the tested population increases (Correct answer)
- Test sensitivity decreases
- Specificity decreases
- Sample size decreases
Correct answer: Disease prevalence in the tested population increases
PPV (probability a positive test is truly positive) rises when the disease is more prevalent in the population being tested, because there are more true positives relative to false positives.
Question 3: A systematic review that mathematically pools data from multiple RCTs to increase statistical power is called a:
- Meta-analysis (Correct answer)
- Narrative review
- Scoping review
- Cohort synthesis
Correct answer: Meta-analysis
Meta-analysis combines quantitative data from multiple studies using statistical methods to derive more precise pooled estimates of treatment effects.
Question 4: Anchoring bias in clinical decision-making occurs when a physician:
- Relies too heavily on the first piece of clinical information and fails to adjust sufficiently (Correct answer)
- Dismisses a diagnosis because it is rare
- Orders too many unnecessary tests
- Avoids uncertainty by defaulting to watchful waiting
Correct answer: Relies too heavily on the first piece of clinical information and fails to adjust sufficiently
Anchoring bias causes physicians to remain fixed on an initial impression even when subsequent information suggests a different diagnosis.
Question 5: In a clinical study, internal validity refers to:
- Whether the study results accurately reflect the true effect in the study population (Correct answer)
- Whether results can be generalized to other populations
- The statistical power of the study
- The reliability of the measuring instrument
Correct answer: Whether the study results accurately reflect the true effect in the study population
Internal validity reflects how well the study design eliminates bias and confounding to establish that the observed association is real within the study population.
Question 6: Which type of error occurs when a study fails to detect a true difference between groups because of insufficient sample size?
- Type II error (beta error) (Correct answer)
- Type I error (alpha error)
- Systematic bias
- Random measurement error
Correct answer: Type II error (beta error)
A Type II (beta) error is a false negative — failing to detect a real difference due to inadequate statistical power, often caused by too small a sample size.
DO Diagnostic Reasoning and Evidence-Based Medicine 2
Which approach to clinical decision-making integrates the best available research evidence with clinical expertise and patient values?