Assessing self-reported disability in a low-literate population with chronic low back pain: cross-cultural adaptation and psychometric testing of Igbo Roland Morris disability questionnaire

Purpose: Cross-culturally adapt and validate the Igbo Roland Morris Disability Questionnaire. Method: Cross-cultural adaptation, test-retest, and cross-sectional psychometric testing. Roland Morris Disability Questionnaire was forward and back translated by clinical/non-clinical translators. An expert committee appraised the translations. Twelve participants with chronic low back pain pre-tested the measure in a rural Nigerian community. Internal consistency using Cronbach's alpha; test-retest reliability using intra-class correlation coefficient and Bland-Altman plot; and minimal detectable change were investigated in a convenient sample of 50 people with chronic low back pain in rural and urban Nigeria. Pearson's correlation analyses using the eleven-point box scale and back performance scale, and exploratory factor analysis were used to examine construct validity in a random sample of 200 adults with chronic low back pain in rural Nigeria. Ceiling and floor effects were investigated in the two samples. Results: Modifications gave the option of interviewer-administration and reflected Nigerian social context. The measure had excellent internal consistency (alpha = 0.91) and intraclass correlation coefficient (ICC =0.84), moderately high correlations (r > 0.6) with performance-based disability and pain intensity, and a predominant uni-dimensional structure, with no ceiling or floor effects. Conclusions: Igbo Roland Morris Disability Questionnaire is a valid and reliable measure of pain-related disability.