Longitudinal Analysis of Disease Burden in Refractory and Nonrefractory Generalized Myasthenia Gravis in the United States

OBJECTIVE: To compare temporal trends in clinical and health care resource utilization (HRU) outcomes in people with refractory and nonrefractory generalized myasthenia gravis (gMG). METHODS: A retrospective analysis of data from adults with gMG in the Myasthenia Gravis Foundation of America Patient Registry. gMG status (ever-refractory or always nonrefractory) and clinical (Myasthenia Gravis—Activities of Daily Living [MG-ADL] scores, exacerbations) and HRU outcomes were determined from questionnaires self-completed 6-monthly for up to 4 years. The probability of each outcome was compared for the 2 groups over time. RESULTS: The mean MG-ADL score and the probability of experiencing each outcome were significantly greater in the ever-refractory versus nonrefractory groups during each year of follow-up. Between-group differences in time trends were statistically significant for intensive care and feeding-tube use. CONCLUSIONS: People who have ever had refractory gMG may have worse functional status, more exacerbations, and higher HRU than people with consistently nonrefractory disease.