Burden of disease in myasthenia gravis: taking the patient's perspective

Abstract

Background: Myasthenia gravis (MG) leads to exertion-dependent muscle weakness, but also psychological and social well-being are limited. We aim to describe the burden of disease in MG including sociodemographic, economical, psychosocial as well as clinical aspects, to compare health-related quality of life (HRQoL) of patients with MG to the general population (genP) and to explore risk factors for a lower HRQoL.

Methods: This case-control study was conducted with MG patients of the German Myasthenia Association. A questionnaire-based survey included sociodemographic and clinical data as well as standardized questionnaires, e.g. the Short Form Health (SF-36). HRQoL was compared to genP in a matched-pairs analysis. Participants of the German Health Interview and Examination Survey for Adults (DEGS1) served as control group.

Results: In our study, 1660 MG patients participated and were compared to 2556 controls from the genP. Patients with MG showed lower levels of physical functioning (SF-36 mean 56.0, SD 30.3) compared to the genP (mean 81.8, SD 22.1, adjusted difference: 25, 95% CI 22-29) and lower mental health sub-score (SF-36 mean 67.3, SD 19.8, vs. 74.1, SD 16.7, adjusted difference: 5, 95% CI 2-8). Female gender, higher age, low income, partnership status, lower activities of daily life, symptoms of depression, anxiety and fatigue and self-perceived low social support were associated with a lower HRQoL in MG patients.

Discussion: HRQoL is lower in patients with MG compared to genP. The burden of MG on patients includes economic and social aspects as well as their emotional well-being. New therapies must achieve improvements for patients in these areas.

Trial registration information: Clinicaltrials.gov, NCT03979521, submitted: June 7, 2019, first patient enrolled: May 1, 2019, https://clinicaltrials.gov/ct2/show/NCT03979521.

Keywords: Burden of disease; Myasthenia gravis; Quality of life; Real-world setting.

Fig. 1

Symptoms of MG Patients according to single-item responses in the MG-ADL score (Activities of daily living). Symptoms were counted as presented if responses other than “normal” were selected by the study participants

Fig. 2

SF-36 domains: Mean values (and standard deviation, SD) of SP (=MG patients in blue) and control group (grey). A Cohen’s d > 0.5 indicates a high effect, 0.3–0.5 medium effect, 0.1–0.3 low effect and < 0.1 no effect

Fig. 3

Net diagrams integrating the Myasthenia gravis Activities of Daily Living Score (MG-ADL), the Myasthenia gravis Quality of life Score (MG-QoL15), the Hospital Anxiety and Depression Scale (HADS), the ENRICHD Social Support Inventory (ESSI-D), the Myasthenia gravis Quality of life Score (MG-QoL15), the Hospital Anxiety and Depression Scale (HADS), the ENRICHD Social Support Inventory (ESSI-D), the Chalder Fatigue Scale (CFQ11) and the Physical Functioning (SF-36 Phys) and Emotional wellbeing (SF-36 Emot) domain of the Short Form 36 (SF-36) in different subgroups: a Gender, b age groups, c groups of different disease severity and d. net household income groups. The further out the lines are in the net, the higher and worse the single score value: Women (a), old patients (b), patients with high disease severity (c) and low income (d) do have the highest burden of disease, composed of high single score value