Abstract
INTRODUCTION: Reported incidence and prevalence rates of Myasthenia Gravis (MG) vary widely and are assumed to have increased over the last few decades. We conducted a nationwide register-based study on the current incidence and prevalence of MG and MG subgroups in Sweden. METHODS: Data were acquired from four Swedish Health Registers in order to identify patients with MG. Incidence and prevalence rates were calculated for the years 2006-2016, using population numbers provided by Statistics Sweden. RESULTS: In 2016, the incidence of MG in Sweden was 2.9 per 100,000 inhabitants (95% CI: 2.5-3.2/100,000) and the crude prevalence was 36.1 per 100,000 inhabitants (95% CI: 34.9-37.3). There was a significant increase in Myasthenia Gravis prevalence from 2006 to 2016. Prevalence rates of all MG subgroups but thymoma-associated MG increased over the same period of time. CONCLUSIONS: The incidence and prevalence of Myasthenia Gravis have increased over time in Sweden, and the rates are high in comparison with other countries.