Validation of the Spanish version of Migraine Disability Assessment questionnaire (MIDAS) in migraine university students.

Background: The Migraine Disability Assessment (MIDAS) questionnaire is widely used to determine the degree of migraine-related disability of subjects. So far, and to the best of our knowledge, no Spanish version of this tool has been validated. The questionnaire comprises seven items, with the first five constituting the main scale while the sixth and seventh items referring, respectively, to the frequency and intensity of headache. The present study aims to analyze the clinimetric properties of the Spanish version of the MIDAS questionnaire in a population of university students. Methods. We performed a cross-sectional study of validation for this measuring instrument. A total of 153 subjects participated in the study. We analyzed construct validity using factor analysis, test-retest reliability by the Intraclass Correlation Coeficient (ICC), internal consistency, and concurrent validity with respect to the 12-Item Short Form Health Survey (SF-12). Results. Factor analysis revealed a two-factor structure. The questionnaire has good reliability for the MIDAS main-scale score ([ICC=0.81; 95% CI: 0.63 – 0.90]), excellent reliability for headache frequency (ICC=0.90; 95%; CI: [0.79 – 0.95]), and moderately good reliability for headache intensity (ICC=0.63; 95% CI: [0.34 – 0.80]). The analysis also yielded good internal consistency results (α Cronbach=0.797) and a moderate correlation between MIDAS-main scale and the physical summary component of SF-12 (Rho=-0.326; p < 0.001). Conclusions. The Spanish version of the MIDAS questionnaire is a valid and reliable tool to measure migraine-related disability in university subjects. The two additional items provide information that could help clinicians in making decisions.