Cross-Cultural Evaluation of the Dutch FACE-Q Rhinoplasty Questionnaires Using Rasch Analysis.

BACKGROUND The English version of the FACE-Q rhinoplasty module was developed according to Rasch measurement theory by Klassen et al. in 2010 and recently translated into Dutch. Before conclusions can be drawn from the Dutch version, this translation must also fit the item analysis by the Rasch model. OBJECTIVES Therefore, the primary outcome of this study was to evaluate the cross-cultural equivalence between the Dutch and English FACE-Q rhinoplasty module applying Rasch methodology. METHODS Using Winsteps ® (Beaverton, OR, USA) for Rasch analysis, the Dutch versions of the FACE-Q nose and nostrils were evaluated on data from a prospective consecutive cohort of 100 Dutch speaking septorhinoplasty patients. New Dutch related conversion tables were constructed for both FACE-Q nose and nostrils and compared to the original ones. Psychometric cross-validation was performed using receiver operating characteristics analysis (ROC). RESULTS Both questionnaires adequately met the requirement of invariance. Within an acceptable range, some issues in item and person fit were found, as well as some local item dependency and differential item functioning. However, the comparison of the Dutch and English related conversion tables with ROC analysis demonstrated identical results for both FACE-Q nose and nostrils. CONCLUSIONS Item analysis by the Rasch model on the data of a Dutch speaking population proved the conceptual correspondence with the original English version.