HINDI TRANSLATION, CROSS-CULTURAL ADAPTATION, VALIDATION AND RELIABILITY OF ISTANBUL LOW BACK PAIN DISABILITY INDEX (ILBPDI) IN PATIENTS WITH CHRONIC MECHANICAL LOW BACK PAIN

Introduction: Globally, Chronic Mechanical Low Back Pain (CMLBP) is a significant cause of disability. Patient-reported outcome measures are essential for assessing functional limitations, however majority of tools now in use were created in Western contexts and might not accurately represent the culturally distinctive daily activities of Hindi-speaking individuals. There is currently no validated Hindi version of the multidimensional Istanbul Low Back Pain Disability Index (ILBPDI), despite its proven psychometric qualities.
Aim: To evaluate the content validity and test-retest reliability following linguistic translation and cultural adaptation of ILBPDI in Hindi for Chronic Mechanical Low Back Pain (CMLBP) patients.
Materials and Methods: This cross-sectional study was conducted at MM Superspeciality Tertiary care Hospital, Mullana-Ambala, India from March 2025 to January 2026. In accordance with Beaton's recommendations, the ILBPDI underwent forward translation, synthesis, backward translation, expert committee evaluation, and pilot testing. The participants included fifty-one Hindi-speaking patients with CMLBP aged between 25-60 years. The Delphi method, which provided Item-Level and Scale-Level Content Validity Indices (I-CVI, S-CVI/Ave and S-CVI/UA), was employed by ten experts to determine content validity. Test-retest reliability was evaluated after 72 hours by Intraclass Correlation Coefficients (ICC), and Internal Consistency (IC) was evaluated by Cronbach's alpha.
Results: Excellent comprehensibility was shown in pilot testing (96-100%). S-CVI/Ave = 0.98 and S-CVI/UA =0.88 indicated strong content validity. The H-ILBPDI demonstrated exceptional test-retest reliability (ICC=0.989) and great internal consistency (Cronbach's α=0.994).
Conclusion: For evaluating functional impairment in Hindi-speaking patients with persistent mechanical low back pain, the H-ILBPDI is a viable, dependable, and culturally relevant instrument.