The Modified Back Beliefs Questionnaire as a tool to screen for incorrect beliefs regarding back pain: Cross-cultural adaptation and measurement properties
Background: The Modified Back Beliefs Questionnaire (MBBQ) evaluates and screen for incorrect beliefs about low back pain (LBP). MBBQ measurement properties remain unknown therefore, a rigorous cross-cultural validation is necessary. Objective: To translate and cross-culturally adapt the MBBQ into Brazilian Portuguese and investigate its measurement properties among physical therapists. Methods: The MBBQ was translated and cross-culturally adapted into Brazilian Portuguese and tested in 30 physical therapists. Then, we evaluated the measurement properties related to reliability and validity in a sample of 100 physical therapists. For the reliability analysis, we calculated test-retest reliability, internal consistency, standard error of the measurement (SEM) and minimal detectable change (MDC). The Pain Attitudes and Beliefs Scale for Physiotherapists (PABS.PT) was used in the construct validity analysis. Results: The reliability analysis showed high internal consistency, good to excellent test-retest reproducibility. The MBBQ inevitability and composite scores showed SEM of 1.9 and 2.4 points and MDC of 5.1 and 6.7 points, respectively. Construct validity analyses showed moderate to excellent correlation of the MBBQ scores and the biomedical subscale of the PABS.PT. Conclusions: MBBQ showed acceptable measurement properties and may be considered a reliable and valid tool to assess patients' beliefs about low back pain.