Translation, cross-cultural adaptation, and psychometric evaluation of the brief illness perception questionnaire into Yoruba language among persons with chronic low back pain

Abstract Background Illness perception may influence the coping behaviors of patients. There is a lack of tools to measure this construct among Yoruba speakers. Therefore, we translate, cross-culturally adapt and determine the reliability and the validity of the Yoruba version of the Brief Illness Perception Questionnaire (BIPQ-Y). Methods The translation and cross-cultural adaptation process was according to Beaton criteria. The psychometric testing of the BIPQ-Y was carried out among 28 consenting patients with low back pain attending a university teaching hospital, while only 10 of them participated in the reliability test. The convergent and discriminant validity of the BIPQ-Y was carried out using the Fear Avoidance Belief Questionnaire and Quadruple Visual Analogue scale. Confirmatory factor analysis was to assess construct validity. Results The mean age of the respondents was 47 ± 15.3 years. The concurrent validity of the BIPQ-Y was excellent ( r = 0.996) for the total score of BIPQ-Y while the internal consistency was moderate (α = 0.52). The test–retest of BIPQ-Y yielded excellent results with item intra-class correlation coefficient (ICC) ranging between 0.833 and 0.973 and an overall ICC of 0.889. For the confirmatory analysis of the BIPQ-Y, the factor loading for the eight items ranged from − 0.071 to 0.799 and the composite reliability was good with a score of 0.68. Conclusion The BIPQ-Y demonstrated excellent psychometric properties that are satisfactory with standards, and it is recommended for assessing illness perceptions of patients with chronic low back pain among the Yoruba-speaking populations.