Reliability |
The degree to which the measurement is free from measurement error |
Internal consistency The degree of the interrelatedness among the items |
Reliability The proportion of the total variance in the measurements which is because of “true” differences among patients |
Measurement error The systematic and random error of a patient’s score that is not attributed to true changes in the construct to be measured |
Validity The degree to which an HR-PRO instrument measures the construct(s) it purports to measure |
Content validity The degree to which the content of an HR-PRO instrument is an adequate reflection of the construct to be measured |
Face validity The degree to which an HR-PRO instrument indeed looks as though they are an adequate reflection of the construct to be measured |
Construct validity The degree to which the scores of an HR-PRO instrument are consistent with hypotheses based on the assumption that a HR-PRO measure validly measures the construct to be measured |
Structural validity The degree to which the scores of an HR-PRO measure are an adequate reflection of the dimensionality of the construct to be measured |
Hypotheses testing Item construct validity |
Cross-cultural validity The extent to which performance of the items from translated or culturally adapted measures adequately replicates the performance of the items from original versions of the measure |
Criterion validity The degree to which the scores of a measure adequately reflect a “gold standard” |
Responsiveness The measure’s sensitivity to changes in the construct to be measured over time |
Interpretability a The extent to which qualitative meaning can be derived from a measure’s quantitative scores or score change |