Evaluating the Cross-Cultural Adaptation, Reliability, and Validity of the Persian Versions of the Copenhagen Neck Function Disability Scale and Neck Bournemouth Questionnaire.

STUDY DESIGN

A cross-sectional study.

OBJECTIVE

To evaluate cross-cultural adaptation and psychometric properties of the Copenhagen Neck Function Disability Scale (CNFDS) and Neck Bournemouth Questionnaire (NBQ) in patients with chronic nonspecific neck pain.

SUMMARY OF BACKGROUND DATA

CNFDS and NBQ are among the most popular scales to investigate aspects of life in patients with chronic neck pain. To date, the Persian versions of these scales have not been validated.

METHODS

Following the translation process, the questionnaires were given to 106 patients with chronic nonspecific neck pain. To evaluate reliability, Cronbach alpha and test-retest reliability were evaluated. To investigate construct validity, the Neck Disability Index (NDI) and Neck Pain Disability Scale (NPDS) were used. Internal consistency of the scales was evaluated with exploratory factor analysis.

RESULTS

No missing data were observed for the NBQ, and missing data affected 0% to 3% of the CNFDS items. There were no floor or ceiling effects. Cronbach alpha was 0.92 for the CNFDS and 0.95 for the NBQ. Test-retest reliability was estimated as 0.86 for the CNFDS and 0.91 for the NBQ. The CNFDS correlated very well with the NDI pain subscale, and the NPDS. The NBQ correlated very well with the NPDS and NDI, and correlated well with the CNFDS and its subscales. Exploratory factor analysis detected three dimensions for the CNFDS and confirmed unidimensionality of the NBQ.

CONCLUSION

The Persian versions of the CNFDS and NBQ have acceptable validity and reliability for use with Persian-speaking patients with chronic nonspecific neck pain.

LEVEL OF EVIDENCE