COSMIN definitions of domains, measurement properties and aspects of measurement properties
| Domain | Measurement property | Aspect of a measurement property | Definition |
| Reliability | The extent to which scores for individuals who have not changed are the same for repeated measurement under several conditions. | ||
| Internal consistency | Different sets of items from the same instrument. | ||
| Test–retest | Changes are repeated measurement over time. | ||
| Inter-rater | The degree of agreement between raters investigating the same property on the same patient. | ||
| Intrarater | The degree of agreement between repeated measurements of a property on the same patient by the same rater. | ||
| Measurement error | The systemic and random error of a patient’s score that is not attributed to true changes in the construct to be measured. | ||
| Validity | How well the instrument under evaluation measures the construct it purports to measure. | ||
| Content validity | The degree to which the score of an instrument is adequate reflection of the construct to be measured. | ||
| Face validity | The degree to which (the item of) an instrument is an adequate reflection of the construct to be measured. | ||
| Construct validity | The degree to which the scores of an instrument are consistent with hypotheses (for instance, with regard to internal relationships, relationships to scores of other instruments or differences between relevant groups) based on an assumption that the instrument truly measures what it is meant to. | ||
| Structural validity | The degree to which the score of an instrument is an adequate reflection of the dimensionality of the construct to be assessed. | ||
| Cross-cultural validity | The degree to which the performance of the items on a translated or culturally adapted instrument are an adequate reflection of the performance of the items of the original version of the instrument. | ||
| Criterion validity | The degree to which measurements are an adequate reflection of a previously used ‘gold standard’. | ||
| Responsiveness | The ability of the measurement instrument to detect change over time in the construct to be measured. | ||
| Interpretability | The degree to which one can assign qualitative meaning, that is, clinical or commonly understood connotations— to an instrument’s quantitative scores or change in scores. | ||
COSMIN, COnsensus-based Standards for the selection of health Measurement INstruments.