Abstract
INTRODUCTION: Oral corticosteroids (OCS) are commonly used to control symptoms in patients with myasthenia gravis (MG). Long-term high-dose OCS use is associated with serious side effects, but the real-world clinical impact of high-dose OCS in patients with MG is not well understood. The main objectives of this study were to evaluate healthcare resource utilization and clinical complications associated with high-dose versus low-dose OCS use in Japanese patients with MG. METHODS: A retrospective cohort study was performed using JMDC, a Japanese claims database. Patients with newly diagnosed MG (incident cases) were identified, and the date of the first diagnosis of MG was defined as the index date. Patients were stratified into two groups by OCS dose level (high-dose OCS ≥ 7.5 mg/day; low-dose OCS < 7.5 mg/day; based on the average dose in the population during the follow-up). Patient characteristics, treatments, long-term hospitalization (≥ 10 days cumulative per year), and corticosteroid-related complications were assessed. RESULTS: Of 2107 patients with an incident MG diagnosis, 576 were on OCS (high-dose OCS, 210; low-dose OCS, 366) during the follow-up period. There were no obvious differences in baseline comorbidities between the high- and low-dose OCS groups. A significant increase in long-term hospitalization was observed in the high-dose OCS versus the low-dose OCS group (adjusted odds ratio [95% CI], 1.832 [1.180, 2.845], P = 0.007). A greater proportion of patients in the high-dose OCS group versus the low-dose OCS group received ≥ 1 course per year of in-hospital intravenous immunoglobulin (34.8% vs. 15.3%), plasma exchange therapy (16.2% vs. 8.2%), and intravenous methylprednisolone pulse therapy (33.3% vs. 24.0%). The incidence of new complications such as diabetes, osteoporosis, osteoporotic fractures, neuropsychiatric disease, and sepsis was significantly (P < 0.05) higher with high- versus low-dose OCS. CONCLUSION: Use of high-dose OCS in patients with MG was associated with adverse outcomes, including increased rates of long-term hospitalizations and clinical complications.