Myasthenia gravis-treatment and severity in nationwide cohort

Myasthenia gravis (MG) is a rare autoimmune disorder of neuromuscular junction. MG healthcare burden has not been studied in Poland before.

Data were drawn from the National Health Fund database; MG patient was defined as a person who received at least once medical service with ICD-10 code MG (G70) and at least two reimbursed prescriptions for pyridostigmine bromide or ambenonium chloride in two consecutive years. We have analyzed treatment: immunosuppression, intravenous immunoglobulins (IVIg), plasma exchange (PE), the number and length of hospitalizations (LOS), intensive care unit (ICU) care, and deaths between 2013 and 2018.

In 2018, there were 9012 MG patients (F:M 1.62:1), and 30.6% had early -onset MG (<50 years). 66.3% received symptomatic treatment only, 33.7%-glucocorticoids (CS) and/or other immunosuppressants (IS), 64.6%-CS only, 17.5%-azathioprine plus CS, 11%-azathioprine only, 4.6%-CS plus other IS (methotrexate, mycophenolate mofetil, cyclosporine, or tacrolimus), and 2%-other IS only. In 2018, 42.3% of patients were hospitalized at least once (mean 2.05/year), 13.7% due to MG (1.47/year). In 2018, 1.63% patients received PE, 2.33% IVIg. In 2013-2018, 2.7%-3.2% of MG patients required hospitalization in ICU. ICU mean LOS 2013-2018 was 11.5-15.0 days/per patient/year. 2.1% of all MG patients had myasthenic crisis. Mean age at death was 75.7 years for MG and 73.9 for general population (p = .006). All-cause mortality was higher for men (4.1%-5.1%) than for women (2.5%-3.1%), p < .01.

Our findings confirm significant healthcare burden of MG, comprising a tool to plan resources needed for MG patients.