The 5-repetition sit-to-stand test as a functional
outcome measure in COPD
Journal Club
September 24, 2013
Presented by Pat Camp and Darlene Reid
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Overview of Journal Club Session
1. Introductions
2. Overview of journal club process
3. Outcome Measures
4. Review of article
a) Rationale
b) Purpose
c) Methods
d) Results
e) Discussion
4. Clinical Implications
5. Wrap Up
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Outcome measure
o a measure that has psychometric properties that
enhance its ability to measure change over time in
an individual or group
o useful outcome measures are
• quantifiable
• available clinically
• practical
• cost-effective
• reliable
• valid
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OUTCOMES
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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
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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?
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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?
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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?
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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
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TABLE 1 FROM PAPER
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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.
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FIGURE 1 FROM PAPER
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TABLE 2 FROM PAPER
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TABLE 3 FROM PAPER
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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.
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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?
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