Development and evaluation of 'neck pain and functional limitation scale': a validation study in the Asian context

Background :There is a paucity of literature on validated outcome measurement tools for evaluation of neck pain and related disability in the Asian context. Aim :The main aim of the present study was to design a new tool called neck pain functional limitation scale (NPFLS) for measuring disability related to neck pain and observe its reliability, concurrent validity and criterion validity. Setting and design :This study was performed at the institutional hospital. Materials and methods :A total of 157 subjects (neck pain group) and 25 control subjects (control group) without neck pain were recruited for this study. NPFLS was framed as a new tool for this study, which consisted of 5 domains - pain intensity, activities of daily living, social activities, functional activities and psychological factors. Neck Bournemouth questionnaire (NBQ) was used as a gold standard to measure the concurrent validity and criterion validity of the NPFLS. Statistical analysis :Criterion validity and concurrent validity between the neck Bournemouth questionnaire (NBQ) and NPFLS scores were tested statistically using Mann-Whitney U test and Spearman correlation test. The reliability was tested by examining the internal consistency to calculate the Cronbach's alpha value for each item in NPFLS. Results : No significant difference between NPFLS and NBQ was observed using Mann-Whitney U Test, with P value greater than 0.05 (P= 0.557). Besides that, NPFLS had a high concurrent validity (r= 0.916) and good internal consistency with high Cronbach's alpha value of (r= 0.948), which demonstrated strong correlation between the items of NPFLS and NBQ. Conclusion : NPFLS demonstrated good reliability, high concurrent validity and criterion validity in this study. NPFLS can be used to assess neck pain and disability among patients with neck pain.