Disease Burden From Myasthenia Gravis Consistently High

Patients in England newly diagnosed with myasthenia gravis receive subpar care due to inconsistent treatment, delayed diagnosis, and limited disease awareness, hindering optimal management of this chronic autoimmune condition through effective disease control. According to new research published in Journal of Neuromuscular Diseases,¹ there also is a significant gap in the clinical literature, even as the disease landscape is evolving.²

For the decade of January 1, 2010, through December 31, 2019, an international team of investigators retrospectively analyzed electronic health records, extracting data on disease burden—which they defined as the presence of comorbidities, health care resource utilization, and disease exacerbations and crises—and treatment patterns for patients with newly diagnosed myasthenia gravis (n = 480).¹ Outcomes were compared with a control group of randomly selected healthy individuals (n = 2237) who did not have myasthenia gravis and were matched 5:1 based on age, sex, and general practitioner practice (857 practices were represented in this study). Patients were identified using clinical Read Codes from the Clinical Practice Research Datalink GOLD database. Only the patients with myasthenia gravis were evaluated for mortality rate, time to death, and frequency of death.

At baseline, more than half of each study group comprised male patients; the mean (SD) patient ages were 67.4 years (15.2) among the patients with myasthenia gravis and 67.4 (14.9) among the healthy controls, and the mean follow-ups were 2.8 (2.3) and 3.1 (2.2) years, respectively. By the end of the study, 16.5% of the patients with myasthenia gravis died, with a mean time to death of 602.6 (621.7) days.

Study Findings

Comorbidities. At baseline, the top 3 most common comorbidities were any infection and hypertension in both groups, followed by type 2 diabetes and anxiety and/or depression. For the follow-up, all comorbidities—dyslipidemia, autoimmune thyroiditis, obesity, osteoporosis, cardiac arrhythmia, other autoimmune disease, type 1 diabetes, ankylosing spondylitis, and systemic lupus erythematosus (SLE) were also seen—were higher in the patients with myasthenia gravis.

For the preindex period of the 12 months prior to the December 31, 2019, index date, mean Charlson Comorbidity Index (CCI) score was statistically significantly higher among the study group vs the healthy group: 0.3 (0.7) vs 0.2 (0.7) (P =.0036). However, when looking at comorbidity grade by severity, the findings were mixed. More patients with myasthenia gravis had mild-grade CCI vs controls (23.8% vs 15.9%; P = .0011), similar amounts from each group had moderate-grade CCI (1.7% vs 1.3%, respectively), and no patients with myasthenia gravis had severe-grade CCI vs 0.4% of the control group.

There were a mean of 2.6 (3.0) disease exacerbations among the cohort with myasthenia gravis—with 63.5% experiencing at least 1 within the follow-up period—and a total incidence rate of 50.0 (95% CI, 44.7-55.9) per 100 person-years. Myasthenic crises were low throughout, with just 3.5% of patients experiencing this, at a mean of 1.3 (0.8) per patient. Per 100 person-years, the rate was 1.3 (95% CI, 0.8-2.0).

There were a mean 2.6 (3.0) disease exacerbations among the patients with myasthenia gravis—with 63.5% experiencing at least 1 within the follow-up period—and a total incidence rate of 50.0 (95% CI, 44.7-55.9) per 100 person-years. | Image Credit: © MohammedElAmine-stock.adobe.com

When looking at the comorbidities, the lowest incident rates were other autoimmune disease (1.8; 95% CI, 1.2-2.7), ankylosing spondylitis (1.6; 95% CI, 1.1-2.5), and SLE (0.9 (95% CI, 0.5-1.6) in the myasthenia gravis cohort and osteoporosis (0.7; 95% CI, 0.5-0.9), ankylosing spondylitis (0.7; 95% CI, 0.5-0.9), and SLE (0.3; 95% CI, 0.2-0.5) in the control group.

Health care utilization. Overall, the cohorts had similar rates of visits to nonneurology specialists (myasthenia gravis cohort, 99.8%; control cohort, 96.4%), but overnight hospitalizations were approximately double in those who had myasthenia gravis (65.0% vs 33.2%), the general practitioner visit rate was higher (94.4% vs 87.3%), the neurology specialist visit rate was much greater (77.1% vs 5.6%), and outpatient visits were increased (98.1% vs 82.4%).

More than half of the patients with myasthenia gravis had at least 1 visit to a nonneurology specialist, and the mean visit total was 2.3 (2.4) visits per patient.

For all-cause and myasthenia gravis–related health care use, the patients with myasthenia gravis had higher rates of emergency department visits (47.1% vs 35.9%) and intensive care unit admissions (12.5% vs 1.8%) compared with the control patients.

Treatment. During follow-up year 1, acetylcholinesterase inhibitors and corticosteroids were used by 56.0% and 50.2%, respectively, of the patients who had myasthenia gravis. Over the remaining study years, however, these rates fluctuated. Acetylcholinesterase inhibitor use dropped through year 9, and corticosteroid use increased for each year of years 2 through 7 as acetylcholinesterase inhibitor use fell. Close to one-third of patients with myasthenia gravis used nonsteroidal immunosuppressive therapies over the study follow-up, with azathioprine (22.9%) being taken the most.

Intravenous immunoglobulin use was seen in more than 10% of patients overall during the follow-up, but the highest yearly rate of 8.1% was seen in the first year after the index date.

Conclusions

With their findings showing the disease burden from myasthenia gravis remains high even after treatment, the study authors explain that access to treatments for these patients needs to come earlier and be more consistent. Treatment also could benefit patients more by addressing the underlying causes of myasthenia gravis and by demonstrating sustained efficacy to mitigate exacerbations as the disease course fluctuates.

“Based on the available data in the literature, increased awareness and a focus on the importance of rapid diagnosis and intervention with high-quality and cost-effective care,” they wrote, “is also needed to reduce the burden on patients, their carers, and an increasingly strained health care system.”

References

1. Bonar K, Boudiaf N, Zaremba P, Tarancón T, Zhou J, Jacob S. Disease burden, healthcare resource utilisation, and treatment patterns in patients with newly diagnosed myasthenia gravis in England: a retrospective cohort study. J Neuromuscul Dis. 2025;12(1):22143602241308194. doi:10.1177/22143602241308194

2. Copley-Merriman K, Miller-Wilson L, Costello J, et al. Evidence gap analysis of the burden of illness and treatment of myasthenia gravis. Value in Health. 2024;27(6):S384-S385. doi:10.1016/j.jval.2024.03.1792