Measurement Reliability Flashcards
What is the difference between reliability & validity?
- Reliability: Stability of the measurement
- Validity: Meaningfulness of the measurement
What are the different types of data?
- Continuous (e.g. TUG)
- Ordinal (e.g. stroke severity: mild, mod, severe)
- Nominal (i.e. categorical, e.g. soccer, AFL, rugby)
- Dichotomous (e.g. injured, not injured)
What are the types of reliability?
- Inter-rater (between different assessors)
- Intra-rater (test-retest, within one assessor)
- Internal consistency (agreement between items that measure the same construct)
What are the methods of measuring reliability?
- Kappa
- Bland-Altman plot
- Minimum detectable change
- Others e.g. intra-class correlation coefficient (ICC)
What is the kappa statistic?
- 50% agreement on any yes/no question, e.g. 50% agreement if two people flip a coin
- Proportion of agreement beyond that expected by chance
What is the formula for the kappa statistic?
k = (observed agreement - chance agreement) / (1 - chance agreement)
What are the other types of kappa?
- Weighted: Gives point for partially correct answer (e.g. mild-mod)
- Prevalence-adjusted bias-adjusted kappa (PABAK): E.g. when yes/no split is 5:95% rather than 50:50
What does method agreement consider?
How an old measurement device compares to a new measurement device
What does the difference between the before & after treatment measurements represent?
- Error of measurement
- Genuine improvement
What is the minimum detectable change?
- How much random noise/error is in a measurement
- Smaller random noise = change more easily detected
What is the standard error of measurement (SEM)?
- Every measurement is made up of the true value +/- error
- SEM = Standard deviation of the error
What does it mean when the difference between the pre-treatment score & post-treatment score is bigger than the MDC?
We are 95% confident a true change has occurred
True or false:
An evidence-practice gap is, by definition, the gap in time which occurs between research evidence generation and when this evidence is routinely integrated into practice
False
The evidence-to-practice pipeline highlights the steps and possible points of ‘evidence leakage’, involved in the path from the generation of research to its use in practice. A health professional who has trouble keeping up with the growing pool of information in their area of practice, is facing a barrier at which step in the pipeline?
Being aware of the evidence
When may a social barrier in the implementation of evidence in practice occur?
When an expectation from a patient that a particular intervention will be provided