Rasch analysis of the Neck Bournemouth Questionnaire: Turkish version, validity, and reliability study

The multidimensional evaluation of patients with chronic neck pain is important for planning the treatment program. The aim of this study was to investigate the validity and reliability of the Turkish version of the Neck Bournemouth Questionnaire (NBQ). The internal construct validity of the NBQ was examined by the fit of the data to the Rasch measurement model. External validity of the NBQ was evaluated by testing for expected associations of Rasch transformed NBQ score with the corresponding variables through the process of convergent validity. The reliability of the NBQ in terms of both internal consistency and test-retest reliability was assessed by the person separation index (PSI) and differential item functioning (DIF) by time effect. It was determined that the questionnaire has 2 factors. None of the items of Factor 1 (F1) and Factor 2 (F2) showed DIF. The reliability of F1 (Cronbach’s alpha = 0.89, PSI = 0.87) and F2 (Cronbach’s alpha = 0.77, PSI = 0.87) was good with Cronbach’s alpha and PSI. There was a good correlation between NBQ/F1 and the Neck Disability Index (NDI) (r = 0.673) and Neck Pain and Disability Scale (NPDS) (r = 0.709). Also, there was a correlation between NBQ/F2 and the Beck Depression Inventory (BDI) (r = 0.552) and Beck Anxiety Inventory (BAI) (r = 0.410). The Turkish version of the Neck Bournemouth Questionnaire is valid and reliable.