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

PURPOSE: 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).

METHODS: Patients were enrolled 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.

RESULTS: 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.

CONCLUSIONS: 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.