DPT Research & Evidence-Based Practice 2 — Questions and Answers
Question 1: A PT wants to determine if a new balance intervention reduces fall risk in elderly patients. Which study design provides the strongest evidence for causality?
- Cross-sectional survey
- Randomized controlled trial (Correct answer)
- Case-control study
- Systematic case series
Correct answer: Randomized controlled trial
Randomized controlled trials (RCTs) are the gold standard for establishing causality because random allocation controls for confounding variables.
Question 2: In a study comparing two gait training methods, researchers report a p-value of 0.03. What does this indicate?
- The treatment effect is clinically meaningful
- There is a 3% probability the results occurred by chance under the null hypothesis (Correct answer)
- The null hypothesis is proven false
- The study has a 97% power
Correct answer: There is a 3% probability the results occurred by chance under the null hypothesis
A p-value of 0.03 means there is a 3% probability of obtaining results as extreme as observed if the null hypothesis were true.
Question 3: Which measure best describes the spread of data around the mean in a normally distributed dataset?
- Interquartile range
- Standard deviation (Correct answer)
- Median
- Mode
Correct answer: Standard deviation
Standard deviation quantifies the average dispersion of data points around the mean in a normal distribution.
Question 4: A systematic review pools results from 12 RCTs on manual therapy. Which statistical method is used to combine their effect sizes?
- Logistic regression
- Meta-analysis (Correct answer)
- Factor analysis
- Discriminant analysis
Correct answer: Meta-analysis
Meta-analysis is the statistical technique used to quantitatively combine and summarize effect sizes from multiple independent studies.
Question 5: When a clinician applies research findings to a patient whose demographics differ from the study sample, which EBP component is being evaluated?
- Internal validity
- Statistical significance
- Applicability (external validity) (Correct answer)
- Measurement reliability
Correct answer: Applicability (external validity)
Applicability or external validity concerns whether study findings can be generalized to patients outside the original study population.
Question 6: A clinician uses the Patient-Specific Functional Scale (PSFS) pre- and post-treatment. The PSFS has an MDC of 2 points. A patient improves by 1.5 points. What is the correct interpretation?
- The patient achieved a clinically meaningful change
- The change may be within measurement error (Correct answer)
- The treatment was ineffective
- The PSFS is not reliable for this population
Correct answer: The change may be within measurement error
A change below the minimal detectable change (MDC) cannot be distinguished from measurement error with confidence.
Question 7: In an EBP framework, which of the following best represents integration of all three core components?
- Following clinical guidelines regardless of patient values
- Combining best research evidence with clinical expertise and patient preferences (Correct answer)
- Relying solely on expert opinion for complex cases
- Applying the most recent published study to every patient
Correct answer: Combining best research evidence with clinical expertise and patient preferences
EBP requires integrating the best available research evidence with clinical expertise and individual patient values and preferences.
DPT Research & Evidence-Based Practice 2
A PT wants to determine if a new balance intervention reduces fall risk in elderly patients.
Which study design provides the strongest evidence for causality?