Samenvatting

Purpose: To translate and culturally adapt the Swedish version of the 'Blue flags' questionnaire into Dutch and to examine the validity and reliability aspects of the Dutch version. Methods: The 'Blue flags' questionnaire was translated and culturally adapted to the Dutch situation. A total of 58 participants filled in the first questionnaire at baseline and 51 participants filled in the second questionnaire sent two weeks later. The data of the participants who filled in the first questionnaire was used to determine internal consistency, structural validity and concurrent validity. The data of the participants who filled in both questionnaires was used to determine test-retest reliability. Results: The internal consistency was good with a Cronbach's alpha of 0.83. The structural validity was satisfactory with a Kaiser-Meyer-Olkin (KMO) test of 0.75 and a significance of p < .001 for the Bartlett's test. Four factors were extracted using principal component analysis (PCA) with varimax rotation with an explained total variance of 70.8%. Spearman's rho for concurrent validity was 0.68 (p < .001). The intraclass correlation coefficient (ICC) for test-retest was 0.80 (p < .001) for the total score. Conclusions: The Dutch version of the 'Blue flags' questionnaire showed good internal consistency, satisfactory structural validity, strong concurrent validity (with mixed item representation results) and strong reliability.