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.