Assessment of pain and disability in patients with chronic neck pain: reliability and construct validity of the Turkish version of the neck pain and disability scale

Objectives : The objective of this study was to test whether a Turkish version of the Neck Pain and Disability Scale retains its reliability and validity of the original English version. Methods : Sixty-one patients with chronic neck pain were enrolled in the study. The Neck Pain and Disability Scale (NPDS), the Pain Disability Index (PDI) and The Hospital Anxiety and Depression Scale (HADS) were filled by all subjects. Reliability was determined by internal consistency. Internal consistency was measured by calculating Cronbach's alpha and item-total correlation. Validity was examined by correlating the NPDS scores to the Visual Analogue Scale (VAS), PDI and HADS scores. Results : Cronbach's alpha value for NPDS was found to be 0.86 and this was statistically significant (p<0.0001). The item-total correlations of NPDS varied between 0.08 and 0.69. The cross-sectional construct validity coefficients were 0.51 for PDI, 0.45 for VAS, 0.35 and 0.33 for Hospital Anxiety and Depression Scales. Conclusion : Despite its major limitations, our results seem to support previous findings of the English and French versions of the Neck Pain and Disability Scale, indicating that this functional scale is valid and reliable.