Table 3.

Quality criteria for measurement properties [Based on Terwee et al., [17]]

Property	Rating	Quality Criteria
Reliability
Internal consistency	+	(Sub)scale unidimensional AND 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
Measurement error	+	MIC > SDC OR MIC outside the LOA
	?	MIC not defined
	-	MIC ≤ SDC OR MIC equals or inside LOA
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
Validity
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
Construct validity
- Cross-cultural validity	+	Original factor structure confirmed OR no important DIF
	?	Confirmation original factor structure AND DIF not mentioned
	-	Original factor structure not confirmed OR important DIF
- Structural validity	+	Factors should explain at least 50% of the variance
	?	Explained variance not mentioned
	-	Factors explain < 50% of the variance
- 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
Responsiveness
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

[..] = reference number, MIC = minimal important change, SDC = smallest detectable change, LOA = limits of agreement, ICC = intraclass correlation coefficient, DIF = differential item functioning, AUC = area under the curve

^† + = positive rating, ? = indeterminate rating, - = negative rating