outcome measures Flashcards
what are outcome measures?
- tool to measure the result of interventions over time
- demonstrate if the interventions are effective and efficient
what are the outcome measure tools?
- test
- measurement
- scale
what are the measures?
- variety of outcome measures
- individualised, generic and condition specific
- measure a particular attribute of interest to patients or clinicians
what are the measures influenced by? when do they change?
- influenced by an intervention
- changes as patient is treated
what are the examples of outcome measures?
- strength
- range of movement
- pain
- psychological measures such as BP, HR, RR, SP02
- distance mobilised
what do we quantify and monitor from outcome measures?
- quantify a patient’s ability
- monitor treatment progress
what do outcome measures facilitate and acquire?
- facilitate clinical decision- making
- acquire baseline data
what do outcome measures determine?
- clinical efficacy
- cost- effectiveness of treatment
what are patient reported outcome measures? give an example
- used to assess outcomes which are important to the patient
- questionnaires
what are patient reported outcome measures used to assess?
- assess outcomes which are important to the patient
what can patient reported outcome measures assess and support?
- assess if treatment plan is working
- support clinical decision making
what does patient reported outcome measures involve and drive?
- involves research and evidence- based practice
- drive quality improvement
what does patient reported outcome measures empower?
- empowers the patient
what can patient reported outcome measures help with ?
- service provision and policy making
how is patient reported outcome measures multidimensional?
- physical, mental and social factors
- known as health- related quality of life tools
what is the advantages of patient reported measures?
+ measures attributes most important to them e.g., QOL so more interesting
what are clinician- reported measures? give an example
- passive clinical tests or performance based measures
- limb girth, isokinetic strength testing
what is the advantage of clinician reported measures ?
- assess what a patient can do, not what they think they can do
- more objective
what are individualised patient reported outcome measures? give an example
- looks at patients’ own definitions of health and the outcomes that are important to them
e.g., patient specific function scale
what are the ten desirable properties of an outcome measure?
- appropriateness
- acceptability
- feasibility
- interpretability
- reliability
- validity
- responsiveness
- low floor and ceiling effects
- internal consistency and dimensionality
- tested with patients of interest
what should you consider when you select an appropriate outcome measure?
- consider the condition you are treating
what are the four things you should think about to select an appropriate outcome measure?
- appropriate
- valid
- reliable
- responsive
what does appropriateness refer to in outcome measures? what are the two types?
- is the measure appropriate for the intended use
- generic or specific
what are the two big factors taken into consideration for appropriateness?
- who is being measured
- what is being measured
how should measures be designed to aid appropriateness?
- measures should be purposely designed for types of patients with whom they will be using
what is a generic patient reported outcome measure? give an example
- measures the response of patients regardless of illness or disorder
- used with most patients as addresses all aspects of QOL
e.g., SF-36
what are specific patient reported outcome measure? give an example
- focuses on specific disease/ disorder and outcomes relevant to condition
- intended for patients who share a particular feature
e.g., neck disability index
what are the three types of specific measures?
- condition- specific
- site- specific
- dimension- specific
what is condition specific?
- same injury/ condition
what is site- specific?
- injury to the same body part
what is dimension specific ?
- same signs and symptoms
what is the advantage and disadvantage of more condition specific measures?
+ more likely to measure outcomes relevant to that condition
- less likely to measure overall health and quality of life
how is what being measured separated into 4 categories?
- body structure impairment
- body function impairment
- activity limitation
- participation limitation
what does body structure impairment refer to?- give an example
- injury itself
- ACL injury> MRI scan
what does body function impairment refer to?- give an example
- signs and symptoms of injury
- muscle weakness> isokinetic strength test
what is activity limitations?- give an example
- inability to perform specific functional activities
- reduced hop distance> hop test
what is participation restrictions?- give an example
- inability to participate in life situations
- can’t play sport: battery of functional fitness test
what does validity refer to in outcome measures?
- outcome measure is testing what it says it is testing
what are the four types of validity?
- face
- content
- criterion
- construct
what is face validity?
- does the measure appear to be valid?
not as important as the others but patients more likely to cooperate in assessments that they perceive to be more relevant
what is content validity?
- is the measure comprehensive?
- extent to which a measure covers all important aspects of constructs being measured
what is content validity applicable to?
- measures comprising more than 1 component
e.g., questionnaire
what is criterion validity?
- do scores on measure correlate with gold standard?
what is construct validity?
- degree to which a measure relates to other measures and variables in accordance with theoretically- derived hypotheses
- convergent, divergent and known- groups validity
what should you look for when evaluating content validity?
- look for evidence that creators were thorough and systematic in selecting components
what are the three components for inclusion?
- literature reviews
- expert panel discussions
- views of patients (focus groups and interview)
what should a measure correlate highly with?
- other measures that assess the same construct and are already known to have excellent validity
what is the limitation of construct validity?
- few gold standards exist so need to assess construct validity instead
what are the three types of construct validity?
- convergent validity
- divergent validity
- known groups validity
what does convergent validity mean?
- does the measure correlate well with related measures
- no comparison with gold standards means high correlations are not expected
- you decide what is acceptable e.g., 0.5
what is divergent validity? what should the correlation be below?
- does the measure correlate poorly with unrelated measures
- measure shouldn’t correlate too strongly with unrelate measures
- below 0.3
what is known- groups validity? what does it discriminate between?
- can the measure detect differences between sub- groups of patients
- measures should discriminate between sub groups who differ in some respect e.g., injury severity or disability level
what does reliability refer to in outcome measures?
- results are reproducible
- measure should provide similar values on repeated administration in unchanged patients
what are the three types of reliability?
- intra- rater
- inter- rater
- test- retest
what is intra- rater reliability?
- extent to which measurements taken by the same person are consistent overtime
what is inter- rater reliability?
- extent to which measurements taken by different people are similar
what is test- retest?
- extent to which patients completing a measure without a rater provide consistent results
- compare results on two different times
how do you quantify reliability? what is no reliability vs perfect?
- quantify via a coefficient
0= no reliability
1= perfect
what does reliability coefficient reflect and tell us?
- reflects extent to which a measure can differentiate between individuals
- tells us whether we can rely on a measure in certain situations
what is a good enough coefficient for groups of patients?
- 0.7
- research
what is a good enough coefficient for individuals ?
- 0.9
- clinical decision making
what are the two types of scales for reliability?
- continuous scale
- categorical scale
give an example of a continuous reliability scale
- hop distance
- intraclass correlation coefficient
give an example of categorical reliability scale
- mild, moderate, severe
- kappa coefficient
other than consistency, what is reliability about?
- population dependent
how do you measure reliability?
true subject variability/ true subject variability + measurement error
what does ratio of measurement error measure?
- how different or not the people you are measuring are
what is reliability influenced by?
- variability
- so no such thing as reliability of a measure
what does responsiveness refer to in outcome measures?
- sensitive to change over time
what else should be measured?
- activities of daily living
- HRQL
what barriers could there be to completing the outcome measures?
- cognitive
- psychological
- socioeconomic status
