Validity and Reliability of the Greek Version of the Multiple Sclerosis International Quality-of-Life Questionnaire

BACKGROUND AND PURPOSE: There are no data regarding psychometrically validated, health-related quality-of-life instruments designed specifically for patients with multiple sclerosis (MS) in Greece. Recently, the MS International Quality-of-Life questionnaire (MusiQoL), a multidimensional, self-administered questionnaire, which is available in 14 languages (including Greek), has been validated using a large international sample. We investigated the validity and reliability of the Greek version of the MusiQoL. METHODS: Consecutive patients with different types and severities of MS were recruited from two tertiary-care centers in Greece. All patients completed the MusiQoL, the Short-Form-36 quality-of-life questionnaire (SF-36), and a symptom checklist at baseline and 21±7 days (mean±SD) later. Data regarding sociodemographic status, MS history, and functional outcome were also collected prospectively. Construct validity, internal consistency, reproducibility, and external consistency were tested. RESULTS: A total of 92 patients was evaluated. The construct validity was confirmed in terms of satisfactory item-internal consistency correlations and scaling success (87.5-100%) of item-discriminant validity. The dimensions of the MusiQoL exhibited high internal consistency (Cronbach's alpha: 0.63-0.96), and reproducibility was satisfactory (intraclass correlation coefficients: 0.69-0.99). External validity testing indicated that the MusiQoL correlated significantly with all SF-36 dimension scores (Spearman's correlation: 0.43-0.76). CONCLUSIONS: The Greek version of the MusiQoL appears to be a valid and reliable instrument for measuring quality of life in Greek MS patients.