Appraising Evidence about self report outcome measures

• Measured objectively by the PT (objective measures) and/or the person’s own perceptions (self-report measures)

• Use evidence to assist in selection of the best outcome measures for your patients

outcome meausres

Appraisal of evidence about outcome measures

• development and / or

• performance

what is study credibility?

• validity screens

• Screen for problems with the study’s design that may bias the results

Did the investigators provide an adequate description of the instrument development process, including identification of participants and methods for item development and selection?

• Description of phenomenon to be captured

• Item development process

• Description of types of questions

• Scoring and interpreting results

• Was the person assessing the participants qualified/trained?

Is the instrument of interest easy to administer?

• objective measures 

• self report measures 

Is the instrument of interest reliable?

Consistency or repeatability of test scores

Statistics?

• Test-retest reliability

• Inter-rater reliability

• Intra-rater reliability

what is internal consistency?

• Examines the consistency within the test

• Can only measure with tests of multiple items

Is the instrument of interest valid?

Does it measure what it intends to measure?

what are 2 types of validity?

• face validity 

• content validity 

what is construct validity ?

• known group analysis

• convergent validity

Is the instrument of interest responsive?

• Ability of the outcome measure to detect change when change in fact has occurred

• ceiling effect

• floor effect

what is ceiling effect?

A limitation of a measure in which the instrument does not register a further increase in a score for the highest scoring individuals

what is floor effect?

further decrease

Can scores on the instrument of interest be interpreted in a meaningful way?

MCID- minimal clinically important difference 

does the evidence apply to your patient?

• Is your patient similar to the patients in the study(ies)?

• Can you administer the instrument appropriately in your clinical setting?

• Does the measure fit within the patient’s expressed values and preferences?

choosing the right outcome meausre

• What specific constructs need to be covered?

• Check for ceiling effects

• Does it have good psychometric properties?

What specific constructs need to be covered?

match it to the scale

Check for ceiling effects

Make sure it is appropriate for your patient

Does it have good psychometric properties?

Reliable, valid, and responsive to change