Brazilian version of the Neck Bournemouth Questionnaire does not have a well-defined internal structure in patients with chronic neck pain

Objective: To investigate the structural validity of the Brazilian version of the Neck Bournemouth Questionnaire in patients with chronic neck pain. Design: Cross-sectional study. Setting: Community participants collected via online platform. Subjects: Participants with neck pain (minimal pain intensity of 3 points at rest on 11-point Numerical Rating Scale), both genders and aged > 18 years old. Main measure: The Numerical Rating Scale, Neck Disability Index, Pain-Related Catastrophizing Thoughts Scale, Tampa Scale of Kinesiophobia and the Neck Bournemouth Questionnaire were completed. Exploratory and confirmatory factor analyses were used to identify dimensionality and to compare different structures of the Neck Bournemouth Questionnaire. Results: We included 103 participants. The sample consisted mostly of adults (mean age = 33.64 years, standard deviation = 10.48 years), females (n = 82, 79.6%), lean, single and with higher education. The exploratory factor analysis with implementation of the parallel analysis identified the one-dimensional structure of the Neck Bournemouth Questionnaire, with a Kaiser-Meyer-Olkin value of 0.80 and Bartlett's test significant (P < 0.05). We observed that all structures tested in this study presented a high amount of residues in confirmatory factor analysis, which were identified by the value of root mean square error of approximation > 0.08 and chi-square/degree of freedom > 3.00. Conclusion: The internal structure of the Brazilian version of the Neck Bournemouth Questionnaire is not clear and well-defined. It was not possible to identify the construct measured by the instrument in individuals with chronic neck pain.