Myasthenia Gravis in Poland: National Healthcare Database Epidemiological Study

Abstract

Introduction: Myasthenia gravis (MG) is a rare autoimmune disorder of the neuromuscular junction. MG epidemiology has not been studied in Poland in a nationwide study before. Methods: Our epidemiological data were drawn from the National Health Fund (Narodowy Fundusz Zdrowia, NFZ) database; an MG patient was defined as a person who received at least once medical service coded in ICD-10 as MG (G70) and at least 2 reimbursed prescriptions for pyridostigmine bromide (Mestinon^®) or ambenonium chloride (Mytelase^®) in 2 consecutive years. Results: On 1st of January 2019, 8,702 patients with MG were receiving symptomatic treatment (female:male ratio: 1.65:1). MG incidence was 2.36/100,000. The mean age of incident cases in 2018 was 61.37 years, 59.17 years for women and 64.12 years for men. Incidence of early-onset MG (<50 years) was 0.80/100,000 and 4.98/100,000 for late-onset MG (LOMG), with male predominance in LOMG. Prevalence was 22.65/100,000. In women, there was a constant increase in prevalence of symptomatic MG from the first decade of life up to 80–89 years. In men, an increase in prevalence appeared in the 6th decade. The highest prevalence was observed in the age group of 80–89 years: 59.65/100,000 in women and 96.25/100,000 in men. Conclusions: Our findings provide information on epidemiology of MG in Poland and can serve as a tool to evaluate healthcare resources needed for MG patients.