Cross-cultural adaptation and validation of the Hausa version of the Oswestry Disability Index 2.1a for patients with low back pain

Study Design: Validation of a translated, culturally adapted questionnaire. Objective: To translate the Oswestry Disability Index (ODI) version 2.1a into Hausa Language and to validate its use in a cohort of patients with low back pain (LBP). Summary of Background Data: The ODI is one of the most commonly used condition-specific questionnaires for assessing functional disability in patients with LBP, yet, no formal cross-culturally adapted and validated Hausa version exists. Methods: The Hausa version of the ODI 2.1a (ODI-H) was developed according to established guidelines. Validation was performed among 200 patients with LBP recruited from both rural and urban Nigeria. Reliability was assessed using internal consistency (Cronbach alpha), test-retest reliability by computing intraclass correlation coefficient, standard error of measurement, and minimal detectable change. Convergent validity was assessed by correlating the ODI-H with Visual Analogue Scale for pain, Fear-Avoidance Beliefs Questionnaire, and finger-floor distance test. Divergent validity was assessed by correlating the ODI-H with age, educational level, and occupational status. Exploratory factor analysis (EFA) and confirmatory factor analysis were also performed. Confirmatory factor analysis was performed with three models: 1) one-factor theory-driven model, 2) two-factor theory-driven model (dynamic and static factors), and 3) a model based on our EFA. Results: The ODI-H had high internal consistency (Cronbach alpha = 0.87) and excellent test-retest reliability (intraclass correlation coefficient = 0.937) with standard error of measurement and minimal detectable change being 3.69 and 10.2 respectively. The construct validity (convergent and divergent validity) is supported as all (6:6, 100%) the a priori hypotheses were confirmed. The EFA yielded a two-factor model explaining 54.3% of the total variance but demonstrated poor fit. The one-factor and two-factor theory-driven model had acceptable fit but the one-factor theory-driven model was better. Conclusion: The ODI-H version 2.1a was transculturally equivalent, reliable, and valid tool for assessing functional disability among Hausa-speaking patients with LBP. The use of this tool can be recommended for future clinical and research purposes