The 5-repetition sit-to-stand test as a functional outcome measure in COPD

1. Journal Club September 24, 2013 The 5-repetition sit-to-stand test as a functional outcome measure in COPD Presented by Pat Camp and Darlene Reid

2. Overview of Journal Club Session Introductions Overview of journal club process Outcome Measures Review of article Rationale Purpose Methods Results Discussion Clinical Implications Wrap Up

3. Outcome measure • a measure that has psychometric properties that enhance its ability to measure change over time in an individual or group • useful outcome measures are • quantifiable • available clinically • practical • cost-effective • reliable • valid

4. OUTCOMES

5. Rationale for the study • Many exercise tests exist for pulmonary rehab and COPD but some of them are difficult to implement in all settings • 1. Incremental shuttle walk test – not done routinely in Canada • 2. 6MWD, need a 30m flat course (hard to do in community), should do 2 tests for learning effect • 3. Gait velocity – need more research on its use in PR

6. Key Question • Is the five-repetition sit-to-stand test (5STS) a reliable and valid functional outcome measure in patients with chronic obstructive pulmonary disease?

7. RELIABILTY VERSUS VALIDITY • RELIABILITY • Three main types: • test-retest reliability – does the measure provide the same answer when testing the same person in the same condition? • Intra-rater reliability – does the same tester come up with the same answer when testing the same person in the same condition, on two or more occasions? • Inter-rater reliability – do different testers come up with the same answer when testing the same person in the same condition, on two or more occasions?

8. Validity • Many different types • Face – has inherent meaning with an initial examination • Construct – measures the issue that its supposed to measure. • Content – covers all aspect of the construct • Criterion – has good correspondence with the gold standard • Convergent – the data from one measure converges i.e. moves towards, or is correlated to the data from the accepted standard measure. • Most studies, in medicine test criterion validity: • Are the values obtained from the tool associated with values taken from a different tool which is already considered to be valid?

9. Methods • Recruitment • Patients with stable COPD, no exacerbation within last 4 weeks, no unstable cardiac disease, no significant neuro disease, no recent lower limb joint surgery • Measurement of 5STS • Straight-backed chair with no arms, against the wall • 48cm high, feet flat on floor, arms crossed across chest • Participants instructed to stand up all the way and then sit down without using arms. Timed after go until end of completed 5th stand

10. TABLE 1 FROM PAPER

11. Bland Altman Plots Correlation – two measures are related to one another (when one goes up, the other goes up or when one goes down, the other goes down). But that doesn’t mean that the values are the same between the two measures; they might not agree. Bland-Altman plots show you the difference between the two measures, and whether those differences change depending on the value of the measurement. They show agreement between the two measures.

12. FIGURE 1 FROM PAPER

13. TABLE 2 FROM PAPER

14. TABLE 3 FROM PAPER

15. Conclusions The 5STS is a reliable and valid measure of function in COPD. It is associated with other measures of function and health status, such as ISW, and quality of life. It shows improvement after pulmonary rehabilitation similar to other outcome measures. It does not have a ceiling effect. It does have a floor effect. Further research is needed to identify its usefulness as a primary outcome measure in clinical trials and as a prognostic indicator of future health events.

16. Discussion Points and Clinical Implications What outcome measures do you use in your program? Do you find they are a good measure of function in your patients? Would the 5STS be a feasible additional measure? What is the point of a MCID?