Validating the Migraine-Specific Quality of Life Questionnaire v2.1 (MSQ) in Italian inpatients with chronic migraine with a history of medication overuse

The purpose of the study is to assess validity, reliability and factor structure of the Italian version of Migraine-Specific Quality of Life Questionnaire v2.1 (MSQ) in patients suffering from chronic migraine (CM) with a history of medication overuse (MO). Patients were enroled at hospital admission for withdrawal from MO. Factor analysis was used to confirm the latent structure of the MSQ. Reliability was measured with Cronbach's alpha coefficient, item-total correlation and inter-item correlation. Construct validity was assessed with Pearson's coefficient and known-group analysis. The three-factor structure is basically confirmed. Cronbach's alpha varied between 0.85 and 0.92; item-total correlations were on average higher than 0.70; average inter-item correlation ranged between 0.63 and 0.65. Correlations were all significant; known-group analysis shows that MSQ score was lower consistently with disease severity. Our findings confirm the factor structure, reliability and validity of the MSQ and expand results of previous validation studies to the Italian language and to a group of patients with severe CM requiring withdrawal treatment for MO.