Cross-cultural adaptation and psychometric evaluation of the Yoruba version of the Back beliefs questionnaire among patients with chronic low-back pain

Purpose To translate, culturally adapt and conduct a psychometric evaluation of the Yoruba version of the Back Beliefs Questionnaire (BBQ) among patients with chronic low-back pain. Methods The English version of the BBQ was translated into the Yoruba language through a process of forward-backward translation, reconciliation and harmonization of the reconciled items sequentially. Thereafter, Cronbach's Alpha, Intra-Class Correlation (ICC), Bland-Altman's analysis were used to determine the internal consistency, test-retest reliability and limits of agreement of the Yoruba version of the BBQ (BBQ-Y). Other psychometric properties of the BBQ-Y explored comprised acceptability, standard error of measurement (SEM), minimal detectable change (MDC), convergent validity and floor and ceiling effects. While 119 respondents participated in the validity testing, only 51 of them were involved in the reliability testing of the BBQ-Y. Data were analysed using descriptive and inferential statistics. Alpha level was set at p < 0.05. Results The mean age of the respondents all the respondents was 56.8 +/- 8.5 years. The BBQ-Y had excellent acceptability with a global Cronbach Alpha score of 0.71. The SEM and MDC of the BBQ-Y were 2.3 and 6.4. The BBQ-Y ICC score for test-retest was 0.89, while the Bland-Altman analysis showing limits of agreements for the test-retest reliability were - 6.84 and 5.70. The convergent validity of the BBQ-Y showed a weak correlation (r = 0.273, p = 0.001) with pain intensity using the visual analogue scale. Conclusion This is the first study to culturally adapt the BBY-Y and determined its psychometric properties. The BBQ-Y has adequate psychometric properties and it is an appropriate outcome measure for use among Yoruba speaking patients with chronic low-back pain.