Presentation (CTI)

OBJECTIVES: To analyze the progression of disability and associated costs in incident early-onset myasthenia gravis (MG) patients over a 5-year follow-up period.
METHODS: A retrospective, longitudinal cohort study was conducted using the French national health insurance claims database (SNDS) from January 2013 to December 2020. Early-onset MG was defined as onset before age 50. Disability progression, as measured by disability status (eligibility for Disability Living Allowance), and sick leave were assessed. Costs associated with disability were evaluated over the 5 years of follow-up and compared to the overall incident MG cohort. A generalized estimating equation (GEE) model explored the disability progression over the time.
RESULTS: Among 14,459 MG patients, 1,802 were incident early onset MG (mean age: 35.7 years, SD 8.94; 66% female). During follow-up, 56% took sick leave, with 40% occurring in the first year. Over time, 17% transitioned to disability status, increasing from 4% in year 1 to 19% by year 5. The mean annual disability cost per patient rose by 59%, from €5,118 in year 1 to €8,150 in year 5. Comparatively, the overall incident MG cohort experienced a lower disability rate increase (6% to 11%) and a 39% rise in costs (from €5,432 to €7,563). The GEE model confirmed that age and follow-up duration significantly drive disability progression with odds ratio (OR) increasing from 1.88 at year 1 to 3.05 at year 2, and 4.95 by year 5.
CONCLUSIONS: Disability progression in incident early-onset MG patients is substantial, with rising costs over time and a notable shift from sick leave to disability. Targeted, early interventions are essential to slow disability progression, optimize resource utilization, and improve long-term functional outcomes for this vulnerable patient group.