Cross-cultural adaptation and measurement properties analysis of the Migraine interictal burden scale-4 in Brazilian Portuguese.

OBJECTIVE: To translate, culturally adapt, and validate the measurement properties of the Migraine Interictal Burden Scale-4 (MIBS-4) for Brazilian Portuguese. METHODS: This methodological study included 130 adults with migraine aged 18-55 years: 30 in translation/cross-cultural adaptation and 100 in validation. Participants completed sociodemographic, HIT-6, and MIDAS assessments. Content, construct, convergent, and criterion validity; reliability; sensitivity; and floor/ceiling effects were evaluated.  . RESULTS: The MIBS-4 Brazil demonstrated content validity and comprehensibility (Cohen's κ=0.742, p=.004), acceptable internal consistency (α=0.714), and moderate-to-good test-retest reliability (ICC=0.737; n=52). Confirmatory factor analysis supported a unidimensional structure (CFI=1.000; RMSEA=0.000). Moderate correlations were observed with HIT-6 (r=0.496) and MIDAS (r=0.458). The MIBS-4 explained 30.2% of their combined variance (R2=0.302, p < .001). ROC analysis showed excellent accuracy for HIT-6 (AUC=0.924) and good accuracy for MIDAS (AUC=0.777). No significant floor (11%) or ceiling (2%) effects were found.      . CONCLUSION: The MIBS-4 Brazil is a valid and reliable instrument for assessing interictal migraine burden.