Incremental health care resource utilization, costs, and predictors of high costs in generalized myasthenia gravis

BACKGROUND: The management of patients with generalized myasthenia gravis (gMG) is complex and often involves substantial health care expenses. As the treatment paradigm continues to evolve, understanding the economic burden of gMG must also reflect the availability and increasing use of newly approved and advanced therapies in a diverse patient population. OBJECTIVE: To estimate incremental health care resource utilization (HRU) and costs associated with gMG compared with non-MG controls and identify predictors of high health care costs in gMG in an insured US population cohort. METHODS: Adults with newly diagnosed gMG were identified from Komodo Research data (January 1, 2017, to September 30, 2023). Characteristics of adults without MG were weighted using entropy balancing to match the gMG cohort. The index date was the first MG diagnosis by a neurologist for the gMG cohort and a random date for the non-MG cohort. Annual per patient HRU and health care costs were compared between the weighted cohorts. Predictors of high health care costs were evaluated among the gMG cohort using a logistic regression model. RESULTS: After weighting, among 6,195 patients in the gMG cohort and 226,008 in the non-MG cohort, the mean age was 61.1 years, 49.1% were female, 53.4% were covered by commercial insurance, 41.0% were covered by Medicare Advantage, and 5.6% were covered by Medicaid. The gMG cohort (mean follow-up = 32.7 months) compared with the non-MG cohort (mean follow-up = 31.3 months) had 2.4, 1.6, and 1.9 times more inpatient days, emergency department visits, and outpatient visits annually, respectively (all P < 0.001). Mean annual all-cause total health care costs in the gMG cohort were 43,872 higher than in the non-MG cohort (58,341 vs 14,469; P < 0.001); 59.3% of the difference was driven by pharmacy costs (mostly immunoglobulin). Prediagnosis weakness and fatigue symptoms, exacerbation or crisis, and use of immunoglobulin were important factors significantly associated with high health care costs in the gMG cohort (all P < 0.001). CONCLUSIONS: Despite advances in treatment, the economic burden of gMG remains substantial. Association of high health care costs with early symptoms and disease exacerbations underscores the need for more effective intervention strategies to improve disease control and reduce HRU and costs in patients with gMG.