Outcome measures and evidence-based practice

30 Gulf Prometric Physiotherapist (DHA, DOH, MOH, SCFHS, QCHP) practice questions on Outcome measures and evidence-based practice, part of Clinical Decision Making and Differential Diagnosis. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Medium

   Which description fits the responsiveness of an outcome measure?

   1. AIts ability to predict a future event
   2. BIts ability to measure the intended construct
   3. CIts ability to give the same score on repeat testing
   4. DIts ability to detect true change over time

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   Answer: D · Its ability to detect true change over time

   Responsiveness is the ability of a measure to detect real change when it has occurred, such as after treatment. It is required whenever a tool is used to monitor progress. A reliable measure can still be poorly responsive.

   • A: Predicting a future event describes predictive validity.
   • B: Measuring the intended construct describes validity.
   • C: Repeatability describes reliability.

   Remember this

   Responsiveness is the ability of a measure to detect true change over time.

2. Question 2 · Medium

   A trial of 12 patients finds no difference between two exercise programmes, but a larger later study shows a clear difference. The first trial most likely made which error?

   1. AType II error
   2. BSelection bias only
   3. CRecall bias
   4. DType I error

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   Answer: A · Type II error

   A type II error is failing to detect a difference that truly exists, and it is most often caused by too small a sample, giving low power. A type I error is finding a difference that is not real. Power calculations before the study help prevent it.

   • B: Selection bias can distort results but does not explain a null result caused by small size.
   • C: Recall bias concerns remembering past exposures.
   • D: A type I error is a false positive finding.

   Remember this

   A type II error is missing a real difference, usually because the sample is too small.

3. Question 3 · Hard

   In a study of 200 patients, a special test gave 40 true positives, 10 false positives, 20 false negatives and 130 true negatives. What is the positive predictive value?

   1. A67%
   2. B80%
   3. C93%
   4. D87%

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   Answer: B · 80%

   The positive predictive value is true positives divided by all positive tests: 40 / (40 + 10) = 80%. Sensitivity is 40/60 = 67%, specificity 130/140 = 93% and negative predictive value 130/150 = 87%. Predictive values depend on the prevalence in the sample.

   • A: 67% is the sensitivity.
   • C: 93% is the specificity.
   • D: 87% is the negative predictive value.

   Remember this

   PPV equals true positives divided by all positive tests.

4. Question 4 · Medium

   After a low-speed rear-end car crash, an alert driver has neck pain. Under the Canadian C-spine rule, which finding places him in the high-risk group that needs radiography?

   1. ADelayed onset of the neck pain
   2. BBeing able to sit in the waiting room
   3. CParaesthesia in the arms after the crash
   4. DNo midline cervical tenderness

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   Answer: C · Paraesthesia in the arms after the crash

   The Canadian C-spine rule lists three high-risk factors that call for imaging: age 65 or over, a dangerous mechanism, or paraesthesia in the extremities. Low-risk factors, such as sitting in the waiting room, delayed onset of pain or no midline tenderness, allow the clinician to test active rotation instead.

   • A: Delayed onset of neck pain is a low-risk factor.
   • B: Sitting in the waiting room is a low-risk factor.
   • D: Absence of midline tenderness is a low-risk factor.

   Remember this

   Canadian C-spine rule high-risk factors: age 65 or over, dangerous mechanism, limb paraesthesia.

5. Question 5 · Medium

   In a randomised trial some participants did not complete their allocated exercise programme. Which analysis keeps the benefits of randomisation?

   1. AExcluding all participants with missing data
   2. BAnalysing only those who completed the programme
   3. CAnalysing every participant in the group they were originally assigned to
   4. DMoving non-completers into the other group

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   Answer: C · Analysing every participant in the group they were originally assigned to

   Intention-to-treat analysis includes all randomised participants in their original groups, whatever they actually received. This preserves the balance created by randomisation and gives a realistic estimate of effect. Per-protocol analysis can bias results.

   • A: Excluding participants with missing data removes the information that intention-to-treat retains.
   • B: Analysing only completers is a per-protocol analysis and breaks the balance.
   • D: Reassigning participants defeats randomisation.

   Remember this

   Intention-to-treat analysis keeps participants in their original groups to preserve randomisation.

6. Question 6 · Easy

   Which study design best controls for unknown confounders when comparing two treatments?

   1. ACross-sectional survey
   2. BCase series
   3. CRandomised controlled trial
   4. DCase-control study

   Answer and explanation in LearnFree account

7. Question 7 · Easy

   Which outcome measure asks patients to name activities they find hard and rate their own ability to do each one on a 0-10 scale?

   1. APatient-Specific Functional Scale
   2. BModified Ashworth Scale
   3. CBerg Balance Scale
   4. DSix-Minute Walk Test

   Answer and explanation in LearnFree account

8. Question 8 · Medium

   A study identifies 80 patients with a chronic tendinopathy and 80 without it, then compares their past use of fluoroquinolone antibiotics. Which design is this?

   1. ACase report
   2. BCase-control study
   3. CRandomised controlled trial
   4. DProspective cohort study

   Answer and explanation in LearnFree account

9. Question 9 · Medium

   Which outcome measure is a patient-reported questionnaire designed specifically for disability caused by low back pain?

   1. AWestern Ontario and McMaster Universities Osteoarthritis Index
   2. BNeck Disability Index
   3. COswestry Disability Index
   4. DDisabilities of the Arm, Shoulder and Hand questionnaire

   Answer and explanation in LearnFree account

10. Question 10 · Medium

    A special test with fixed sensitivity and specificity is moved from a specialist clinic, where the condition is common, to general screening, where it is rare. How does its positive predictive value change?

    1. AIt stays the same
    2. BIt becomes equal to the sensitivity
    3. CIt rises
    4. DIt falls

    Answer and explanation in LearnFree account

11. Question 11 · Medium

    A patient is on day three after hip arthroplasty with calf swelling, pitting oedema and tenderness along the deep veins. Which tool estimates the pretest probability of deep vein thrombosis?

    1. AWells clinical prediction rule
    2. BOswestry Disability Index
    3. CBerg Balance Scale
    4. DOttawa knee rule

    Answer and explanation in LearnFree account

12. Question 12 · Hard

    A large trial reports that a new exercise reduced pain by a mean of 6 mm on a 100 mm VAS compared with control (p = 0.01). The MCID is 20 mm. Which conclusion is best?

    1. AClinically important because p is below 0.05
    2. BNeither statistically nor clinically significant
    3. CStatistically significant but probably not clinically important
    4. DClinically important but not statistically significant

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13. Question 13 · Hard

    A measure has a standard deviation of 8 points and a test-retest ICC of 0.91. What is the approximate minimal detectable change at 95% confidence (MDC95 = 1.96 x SEM x square root of 2)?

    1. A9.4 points
    2. B6.7 points
    3. C4.7 points
    4. D2.4 points

    Answer and explanation in LearnFree account

14. Question 14 · Medium

    A patient's disability score improves by 4 points after treatment. The minimal detectable change at 95% confidence for the scale is 6 points. Which interpretation is best?

    1. AThe change proves the treatment worked
    2. BThe scale is invalid
    3. CThe change lies within measurement error
    4. DThe change is clinically important

    Answer and explanation in LearnFree account

15. Question 15 · Medium

    Two therapists independently classify 100 patients as positive or negative on a clinical test. Which statistic best describes agreement beyond chance?

    1. APearson correlation
    2. BStandard deviation
    3. CCohen's kappa
    4. DIntraclass correlation coefficient

    Answer and explanation in LearnFree account

16. Question 16 · Medium

    A 74-year-old woman at a Doha clinic scores 42 out of 56 on the Berg Balance Scale. Which interpretation is most appropriate?

    1. AIncreased risk of falls, so balance training and aid assessment are needed
    2. BA risk of falls only when walking outdoors
    3. CNormal balance, so no further assessment is needed
    4. DA diagnosis of vestibular failure

    Answer and explanation in LearnFree account

17. Question 17 · Easy

    A physiotherapist measures knee flexion with a goniometer twice on a stable patient within ten minutes and gets 95 degrees and 118 degrees. Which measurement property is most clearly poor?

    1. AValidity
    2. BFloor effect
    3. CReliability
    4. DResponsiveness

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18. Question 18 · Hard

    Before referring for nerve conduction studies, a therapist uses a cervical radiculopathy cluster with a sensitivity of 90% and a specificity of 75%. What is the cluster's negative likelihood ratio?

    1. A7.5
    2. B3.6
    3. C0.13
    4. D0.33

    Answer and explanation in LearnFree account

19. Question 19 · Medium

    A clinician asks: 'In adults with chronic neck pain, does cervical stabilisation exercise compared with general exercise reduce disability?' Which PICO element is 'general exercise'?

    1. AComparison
    2. BIntervention
    3. COutcome
    4. DPopulation

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20. Question 20 · Medium

    In a trial of a new mobilisation technique, the physiotherapist who measures the outcome does not know which group each patient is in. This mainly reduces which bias?

    1. ADetection bias
    2. BSelection bias
    3. CAttrition bias
    4. DPublication bias

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21. Question 21 · Medium

    Which patient-reported outcome measure is validated for people with osteoarthritis of the knee and hip, scoring pain, stiffness and physical function?

    1. AFugl-Meyer Assessment
    2. BWOMAC
    3. CBarthel Index
    4. DOswestry Disability Index

    Answer and explanation in LearnFree account

22. Question 22 · Medium

    What does the minimal clinically important difference (MCID) of an outcome measure represent?

    1. AThe smallest change that patients perceive as beneficial
    2. BThe change smaller than measurement error
    3. CThe largest change expected after treatment
    4. DThe smallest change that is statistically significant

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23. Question 23 · Hard

    A lumbar stenosis test is positive in 75 of 100 patients who have the condition and in 5 of 100 who do not. What is its positive likelihood ratio?

    1. A15
    2. B1.7
    3. C7.5
    4. D0.26

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24. Question 24 · Medium

    At the first visit, most patients with mild shoulder disability already score near the maximum on a functional scale. Which limitation does this describe?

    1. ALow specificity
    2. BRecall bias
    3. CCeiling effect
    4. DFloor effect

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25. Question 25 · Easy

    Which test requires the patient to rise from a standard chair, walk 3 metres, turn, walk back and sit down, with the time recorded in seconds?

    1. AFunctional Reach Test
    2. BSix-Minute Walk Test
    3. CBerg Balance Scale
    4. DTimed Up and Go

    Answer and explanation in LearnFree account