Comparison of the Quantitative Myasthenia Gravis and Myasthenia Gravis Activity of Daily Living Scores From a Clinical Practice Perspective

Introduction/Aims Myasthenia gravis (MG) is characterized by fluctuating symptoms, making the assessment of disease activity challenging. Discordance between the clinician‐reported quantitative myasthenia gravis (QMG) score and the patient‐reported MG activity of daily living (MG‐ADL) has previously been observed. We aimed to compare QMG and MG‐ADL in a clinical practice setting and to relate to the quality‐of‐life instrument myasthenia gravis quality of life 15 (MG‐QoL‐15). Methods MG patients simultaneously assessed by QMG, MG‐ADL, and MG‐QoL‐15 ( n = 177) identified in the Swedish MG registry were included. The distribution of total scores for QMG and MG‐ADL and per‐item score discordance was investigated using the Chi‐squared test and paired t‐tests. Multivariate linear regression models were constructed to identify factors associated with QMG and MG‐ADL. Results MG‐ADL exhibited a lower floor effect compared to QMG (14% vs. 28%, p = 0.002) and patients reported significantly worse scores with MG‐ADL than QMG, particularly in bulbar and respiratory items (for breathing item 38% MG‐ADL > QMG vs. 5% MG‐ADL < QMG score). Multivariate analysis revealed that new‐onset status, MG‐QoL‐15 score, and a history of prednisolone treatment were significantly associated with QMG scores, whereas only MG‐QoL‐15 was significantly associated with MG‐ADL. These associations were driven by symptom‐associated questions in MG‐QoL‐15, while the emotional well‐being questions were associated with neither QMG nor MG‐ADL. Discussion We observed that MG‐ADL more readily identified residual symptoms in patients with mild disease activity compared to QMG; however, with a stronger influence of quality of life, suggesting a complementarity of the two scores in clinical practice.