Complications and Occurrence of Exacerbations in Patients with Myasthenia Gravis Treated with Oral Corticosteroids

BACKGROUND: Myasthenia gravis is a rare disease characterized by autoantibody-driven impairment of neuromuscular junction activity. Standard-of-care therapy includes oral corticosteroids (OCS), despite associated complications. This study describes OCS-related complications and exacerbations in a real-world myasthenia gravis population. METHODS: Data Mart Database) to identify patients with myasthenia gravis (International Classification of Diseases, Tenth Revision, Clinical Modification: G70.00/01). Patients were classified into non-OCS and OCS cohorts; the OCS cohort was further stratified into < 6-month, 6-month, and 12-month exposure groups (≥ 5 mg/day prednisone-equivalent; 12-month follow-up). Inverse probability treatment weighting balanced baseline characteristics. Weighted prevalence ratios of select complications (e.g., diabetes, fracture, hyperlipidemia, hypertension, infection, myocardial infarction, osteoporosis, stroke, glaucoma) and rate/risk ratios for exacerbations were calculated. RESULTS: The weighted population included 3297 patients in the non-OCS cohort and 418, 872, and 1243 patients in the < 6-month, 6-month, and 12-month OCS exposure groups, respectively. During follow-up, the < 6-month, 6-month, and 12-month OCS exposure groups had significantly higher infection risk versus non-OCS: weighted prevalence ratios (95% confidence interval) 1.6 (1.1-2.1), 1.5 (1.2-2.0), and 1.6 (1.3-2.0), respectively. Osteoporosis risk was similar in the < 6-month group but higher in the 6- and 12-month groups versus non-OCS: weighted prevalence ratios (95% confidence interval) 1.2 (0.9-1.6), 1.5 (1.2-1.8), and 1.7 (1.4-2.0), respectively. Oral corticosteroid exposure groups had more myasthenia gravis exacerbations during follow-up versus non-OCS. CONCLUSIONS: After adjusting for observable confounders, OCS exposure within the 12-month initiation period was associated with a higher burden of complications and exacerbations among patients with myasthenia gravis.