Patient-reported burden of myasthenia gravis: baseline results of the international prospective, observational, longitudinal real-world digital study MyRealWorld-MG

Abstract

Objectives: Myasthenia gravis (MG) is a rare, chronic, autoimmune neuromuscular disease which can affect functional and mental aspects of health and health-related quality of life (HRQoL). This study aims to obtain detailed knowledge of the impact of MG on HRQoL in a broad population from the perspective of the patient.

Design: Prospective, observational, digital, longitudinal real-world study.

Setting: Adult patients with MG from seven countries (USA, Japan, Germany, UK, Italy, Spain and Canada) downloaded a mobile application onto their phones and entered data about themselves and their MG.

Outcome measures: Data was collected using the following general and disease-specific patient-reported outcome measurements: EuroQol 5 Domains Health-Related Quality of Life Questionnaire (EQ-5D-5L), Myasthenia Gravis Activities of Daily Living (MG-ADL), Myasthenia Gravis Quality of Life 15-item revised scale (MG-QoL-15r), Hospital Anxiety and Depression Scale (HADS) and Health Utilities Index III (HUI3). Patients were categorised by their self-assessed Myasthenia Gravis Foundation of America (MGFA) class (I-V).

Results: Baseline results of 841 participants (mean age 47 years, 70% women) are reported . The distribution across the MGFA classes was: 13.9%, 31.0%, 38.1%, 15.5% and 1.6% for classes I-V. The MGFA class was a strong predictor of all aspects of HRQoL, measured with disease-specific and with generic instruments. The domains in which patients with MG most frequently mentioned problems were usual activities, anxiety and depression, tiredness, breathing and vision. The mean total MG-ADL Score was positively associated with increasing MGFA classes: 2.7, 4.4, 6.3 and 8.4 for MGFA classes I-IV. Mean baseline EQ-5D-5L utility was also associated with MGFA classes and was 0.817, 0.766, 0.648 and 0.530 for MGFA class I-IV.

Conclusions: MG has a large impact on key aspects of health and HRQoL. The impact of this disease increases substantially with increasing disease severity.

Keywords: Adult neurology; NEUROLOGY; Neuromuscular disease.

Conflict of interest statement

Competing interests: SD is the principal investigator of the study, and MFJ has been commissioned by argenx BV and received honoraria to design the study, analyse and report the data. ML is CEO and owner of Vitaccess, who has been commissioned by argenx BV to carry out the data collection. CQ and LD are employees of Vitaccess. GP, SP, JB and SC are employees of argenx BV, the sponsor of the study. SD and MFJ are members of the EuroQol Group. KGC has received advisory board honoraria, speaker fees and funding for research from Alnylam, Biogen, CSL Behring and Sanofi-Genzyme; and travel reimbursement from Sanofi-Genzyme. KGC holds the Emil von Behring Chair in Neuromuscular and Neurodegenerative Disorders, sponsored by CSL Behring. HM has served as a paid consultant for argenx BV, Alexion Pharmaceuticals, Ra Pharmaceuticals and UCB Pharma and has received speaker honoraria from the Japan Blood Products Organisation and research support from the Ministry of Health, Labour and Welfare, Japan. RM has received speaking honoraria from BioMarin, Alexion and UCB, served on advisory boards for Alexion, argenx BV and UCB and received support for congress participation from Merck, Teva and Biogen. FS has received public speaking honoraria from Biogen, Mylan, Novartis, Roche, Sanofi and Teva; and served on advisory boards for Almirall, argenx BV, AveXis, Biogen, Forward Pharma, Merk, Novartis, Novatek, Pomona, Roche and Sanofi.

© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Participant flow. The flowchart shows the distribution of the total number of patients at baseline by country who responded to at least one item, followed by the percentage of respondents for each PROM/survey section. Abbreviations: App, smartphone application; EQ-5D-5L, EuroQol 5 Domains Health-Related Quality of Life Questionnaire; HADS, Hospital Anxiety and Depression Scale; MG-ADL, Myasthenia Gravis Activities of Daily Living; MG-QoL15r, Myasthenia Gravis Quality of Life 15-item revised scale.

Figure 2

Bubble plot of the utility value by MG-ADL (A) and plot of utility regression in function of the MG-ADL (B). (A) The distribution of utilities for each MG-ADL Score with the size of the bubbles representing the number of observations. (B) This regression analysis shows the graphical and numerical association between the MG-ADL and the utility values, with the utility as dependent and MG-ADL total scores as independent variable. MG-ADL: Myasthenia Gravis Activities of Daily Living; EQ-5D-5L: EuroQol 5 Domains Health-Related Quality of Life Questionnaire.