Table 1 Quality Criteria for Measurement Properties (Terwee et al. 2007) [50]

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 all 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

?

Explained variance not mentioned

(−)

Factors explain <50 % of the variance

 Hypothesis testing

(+)

Correlation with an instrument measuring the same construct ≥50 % OR atleast 75 % of the results is 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 <50 % OR <75 % of the results is in accordance with the hypotheses OR correlation with related constructs is lower than with unrelated constructs