Table 4.
Measurement Property | Reported Result | Quality Criteriaa |
---|---|---|
Reliability | ||
1. Internal consistency | + | (Sub)scale unidimensional OR Cronbach's alpha(s) ≥ 0.70 |
? | Dimensionality not known OR Cronbach's alpha not determined | |
– | (Sub)scale not unidimensional OR Cronbach's alpha(s) ≤ 0.70 | |
0 | Did not assess internal consistency | |
2. Reliability | + | ICC/weighted Kappa ≥ 0.70 OR Pearson's r ≥ 0.80 |
? | Neither ICC/weighted Kappa, nor Pearson's r determined | |
– | ICC/weighted Kappa <0.70 OR Pearson's r < 0.80 | |
0 | Did not assess reliability | |
3. Measurement error | + | MIC > SDC OR MIC outside the LOA |
? | MIC not defined | |
– | MIC ≤ SDC OR MIC equals or inside LOA | |
0 | Did not assess measurement error | |
Validity | ||
4. Content validity | + | The target population considers all items in the questionnaire to be relevant AND considers the questionnaire to be complete |
? | No target population involvement | |
– | The target population considers items in the questionnaire to be irrelevant OR considers the questionnaire to be incomplete | |
0 | Did not assess content validity | |
5. Structural validity | + | Factors should explain at least 50% of the variance |
? | Explained variance not mentioned | |
– | Factors explain < 50% of the variance | |
0 | Did not assess structural validity | |
6. Construct validity (hypothesis testing) | + |
Correlation with an instrument measuring the same construct ≥ 0.50 OR at least 75% of the results are in accordance with the hypotheses AND correlation with related constructs is higher than with unrelated constructs |
? | Solely correlations determined with unrelated constructs | |
– | Correlation with an instrument measuring the same construct < 0.50 OR < 75% of the results are in accordance with the hypotheses OR correlation with related constructs is lower than with unrelated constructs | |
0 | Did not assess construct validity | |
7. Criterion validityb | + | Convincing arguments that gold standard is “gold” AND correlation with gold standard > 0.70 |
? | No convincing arguments that gold standard is “gold” OR doubtful design or method | |
– | Correlation with gold standard !0.70, despite adequate design and method | |
0 | Did not assess criterion validity | |
Responsiveness | ||
8. Responsiveness | + |
Correlation with an instrument measuring the same construct ≥ 0.50 OR at least 75% of the results are in accordance with the hypotheses OR AUC ≥ 0.70 AND correlation with related constructs is higher than with unrelated constructs |
? | Solely correlations determined with unrelated constructs | |
– | Correlation with an instrument measuring the same construct < 0.50 OR < 75% of the results are in accordance with the hypotheses OR AUC < 0.70 OR correlation with related constructs is lower than with unrelated constructs | |
0 | Did not assess responsiveness |
Abbreviations: AUC, area under the curve; ICC, intra‐class correlation coefficient; LOA, limits of agreement; MIC, minimal important change; SD, standard deviation; SDC, smallest detectable change.
These criteria were adapted from Uijen et al.70 unless stated otherwise. The relevant criterion for cross‐cultural validity is not available from the current literature; this precluded rating the quality/adequacy of cross‐cultural validity property in the review.
Adapted from Terwee et al.81