Translation, cross-cultural adaptation and psychometric properties of the Urdu version of the back pain functional scale in low back pain patients

BACKGROUND: Translation and validation of important scales in other languages reduce bias in reporting the functional status of the patient. OBJECTIVE: To translate the Back Pain Functional Scale into Urdu (BPFSu), adapt it for use in other cultures, and evaluate its psychometric properties. METHOD: According to Beaton guidelines, translation and cultural adaption was carried out. On 100 Urdu-literate men and women aged 18-60 years with lower back pain, the final BPFSu was assessed for psychometric qualities. First at baseline and again after 7 days, participants completed the BPFSu, the Functional Rating Index (FRI), and the Numeric Pain Rating Scale (NPRS). RESULTS: Internal consistency of the BPFSu was excellent (Cronbach's alpha: 0.937). No floor and ceiling effects were found Excellent test-retest reliability (ICC = 0.882, CI 95%; 0.830-0.919) was achieved. Spearman correlation coefficient showed criterion validity with the NPRS (rho = 0.701, p 6 0.001) and Pearson correlation coefficient showed construct validity with the FRI (r = 0.740, p 6 0.001). The minimum detectable changes were 9.96, while the standard error of measurement was 3.6. CONCLUSION: The BPFSu is a valid and reliable instrument for assessing physical function in individuals experiencing low back discomfort.