. Author manuscript; available in PMC: 2014 Dec 1.

Published in final edited form as: Qual Life Res. 2013 Mar 29;22(10):10.1007/s11136-013-0395-8. doi: 10.1007/s11136-013-0395-8

Table 1.

Quality criteria for measurement properties adapted from Terwee et al. [37]

Property	Rating	Quality Criteria^a
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 OR no assessment of completeness or comprehensiveness^a
	−	The target population considers items in the questionnaire to be irrelevant OR considers the questionnaire to be incomplete
Construct validity
Structural validity	+	Factors should explain at least 50% of the variance OR Good or adequate fit by goodness-of-fit criteria for a CFA or EFA^a, ^b
	?	Explained variance not mentioned OR equivocal fit by goodness-of-fit criteria for a CFA or EFA^a, ^b
	−	Factors explain < 50% of the variance OR Poor fit by goodness-of-fit criteria for a CFA or EFA^a, ^b
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 OR No evidence of DIF^a
	?	Solely correlations determined with unrelated constructs OR ≥ 50% but < 75% of the results are in accordance with the hypotheses^a OR possible DIF^a
	−	Correlation with an instrument measuring the same construct < 0.50 OR < 50% of the results are in accordance with the hypotheses^a OR correlation with related constructs is lower than with unrelated constructs OR notable evidence of DIF^a
Responsiveness
Responsiveness	+	Correlation of changes with an instrument measuring change in the same construct ≥ 0.50 OR at least 75% of the results are in accordance with the hypotheses OR AUC ≥ 0.70 AND correlation of changes with related constructs is higher than with unrelated constructs
	?	Solely correlations determined with unrelated constructs
	−	Correlation of changes with an instrument measuring change in the same construct < 0.50 OR < 75% of the results are in accordance with the hypotheses OR AUC < 0.70 OR correlation of changes with related constructs is lower than with unrelated constructs

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

Quality criteria are from [37], with modifications by the authors indicated by italics.

Good or Adequate fit: comparative fit index (CFI) ≥ 0.90, root mean square error of approximation (RMSEA) ≤ 0.08, standardized root mean square residual (SRMR) < 0.10 [83-85]; Inadequate fit: CFI ≤ 0.85, RMSEA ≥ 0.10, SRMR ≥ 0.10; Indeterminate fit: the values of fit indexes ranged in between the adequate criteria and inadequate criteria.