Cross-cultural adaptation and validation of the Neck Bournemouth Questionnaire in the Italian population

The aim of this study was to cross-culturally adapt the Neck Bournemouth Questionnaire in Italian (NBQ-I) and validate its psychometric properties in a sample of subjects with chronic neck pain. The NBQ-I was developed according to international standards. The psychometric testing included the content validity, assessed by considering the relevance and comprehensiveness of the items, the structural validity by factor analysis, the construct validity and the responsiveness by mean of hypotheses testing process comparing, respectively, the test scores and the changes scores of the NBQ-I with those of the Neck Pain and Disability Scale, the Numerical Rating Scale for Pain, the EuroQoL 5 Dimension Index and its numerical rating scale. Finally, we tested the reliability by internal consistency (Cronbach's alpha) and the interpretability by calculating the Minimal Clinical Important Difference (MCID). The NBQ-I had acceptable psychometric characteristics. A total of 96 subjects with chronic neck pain completed the questionnaire's administration. The high relevance and comprehensiveness of the items pointed out acceptable face validity. The construct validity analysis was based on the structural validity, which revealed a two factors structure explaining 69.2 % of variance, and on the hypotheses testing process, which showed a moderate validity. The internal consistency was acceptable (alpha = 0.89). The responsiveness, assessed with the hypotheses testing process, was moderate. The MCID was 5.5 points. The validation process revealed acceptable psychometric properties of the NBQ, whose Italian version can be used for research and clinical purposes.