The MG-QOL15 Japanese version: validation and associations with clinical factors.

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.