Low back pain is a common symptom in younger populations but the real functional impact of this condition remains underreported. In the absence of culturally adapted and validated instruments to assess the functional impact of low back pain in Portuguese adolescents, a methodological study was developed aiming to translate and culturally adapt the modified version of the Hanover Functional Ability Questionnaire (MHFAQ) to the European Portuguese language and examine its psychometric properties. The MHFAQ was first translated and back translated following the published guidelines. The Portuguese version of the MHFAQ was then piloted in a Portuguese sample of 40 adolescents with low back pain complaints and assessed for reliability through internal consistency and reproducibility, using Cronbach's alpha and intraclass correlation coefficient (ICC2,1), respectively. Construct validity was assessed using Spearman's correlation analysis between the MHFAQ-PT and the Numeric Pain Rating Scale (NPRS), for convergent validity, and between the MHFAQ-PT and the Health Mental dimension of the Medical Outcomes Study Short-Form Health Survey Instrument 12-Item (SF-12), for discriminant validity, in a new sample of 127 adolescents. One week test-retest reliability was 0.973 (CI: 95%: 0.948-0.986, p < 0.01) and Cronbach's alpha was 0.699, indicating good reliability estimates for the Portuguese version of the MHFAQ. The results showed a moderate positive correlation between MHFAQ-PT and END (rs = 0.591, p < 0.01), and a negative correlation between MHFAQ-PT and Mental Health dimension of the SF-12 (rs = -0.426, p < 0.01). Therefore, the translated and adapted version of MHFAQ is acceptable to assess functional status of Portuguese speaking adolescents with low back pain complaints.
Robalo, L., Cruz, E. B., & Nunes, C. (2016). Modified Hanover Functional Ability Questionnaire: Validation for the Portuguese speaking adolescentes with back pain. Revista Portuguesa de Saude Publica, 34(1), 61–68. https://doi.org/10.1016/j.rpsp.2015.09.001