Domains | Properties | Aspects | Statistics/Methods |
---|---|---|---|
Reliability | |||
 | Internal consistency |  | Cronbach’s alpha or Kuder-Richardson formula (KR-20) to determine relevance |
Factor analysis or principal component analysis to determine whether items form one or more than one scale | |||
Reliability |  | Intraclass correlation coefficient (ICC) or Cohen’s kappa | |
Measurement error | Â | Standard error of measurement (SEM) | |
Smallest detectable change (SDC) | |||
Change beyond measurement error | |||
Limits of agreement (LoA) | |||
Minimal important change to determine the adequacy of measurement error | |||
Validity | |||
 | Content validity | Face validity | Assessment of relevance of all items for the construct, aim and target group |
Assessment of important missing items | |||
Construct validity | Â | Â | |
 | Structural validity | Factor analysis to confirm the number of subscales present | |
Hypotheses testing | Assessment of a priori hypotheses, clearly indicating both direction and magnitude of the correlation or difference | ||
Cross-cultural validity | Assessment of adequate reflection of the performance of the items of the original instrument | ||
Criterion validity | Â | Correlation | |
Area under the receiver operator characteristics curve (AUC) | |||
Sensitivity and specificity | |||
Responsiveness | |||
 |  |  | Assessment of a priori hypotheses focussing on the change score of an instrument in the hypotheses |
Area under the receiver operator characteristic curve (AUC) |