The MG‐QOL15 Japanese version: Validation and associations with clinical factors

Abstract Introduction: Our study aim was to produce a Japanese translation of the 15‐item Myasthenia Gravis Quality‐of‐Life Scale (MG‐QOL15), assess its reliability and validity, and examine clinical factors affecting self‐perceived QOL in MG. Methods: We evaluated 327 consecutive patients with MG seen at six neurological centers. All patients completed the Japanese version of the MG‐QOL15 (MG‐QOL15‐J), the Beck Depression Inventory—second edition (BDI‐II), and a generic health‐related QOL questionnaire, the SF‐36. Disease severity was determined according to the Myasthenia Gravis Foundation of America (MGFA) quantitative MG score and the MG composite. Results: The MG‐QOL15‐J exhibited adequate internal reliability, test–retest repeatability, and concurrent validity with SF‐36, disease severity, and known‐patient groups categorized by MGFA post‐intervention status. Multivariate analysis revealed severity, dose of oral corticosteroids, and BDI‐II as independent factors negatively affecting QOL. Conclusion: The MG‐QOL15‐J is anticipated to be a valuable clinical measure of QOL in Japanese patients with MG. Muscle Nerve 46: 166–173, 2012