Abstract Details

Title Differences in Mortality Among Medicare Beneficiaries With and Without Generalized Myasthenia Gravis

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) P4 - Poster Session 4 (8:00 AM-9:00 AM)

Poster/Presentation
Number 9-018

Objective To assess differences in mortality among Medicare beneficiaries with generalized myasthenia gravis (gMG) and without MG.

Background gMG is a rare autoimmune disorder characterized by loss of neuromuscular function that may progress to life-threatening exacerbation or crisis. While the overall burden of gMG is well documented, real-world mortality data among older adults remain limited.

Design/Methods A prevalent cohort design was used based on the 100% Medicare Fee-for-Service Database (10/01/2019–12/31/2023). The gMG cohort included patients with evidence of active disease (≥1 MG-related admission or ≥2 MG-related visits ≥30 days apart) and ≥1 MG diagnosis confirmed by a neurologist; random MG diagnosis defined index date. The non-MG cohort had no MG diagnoses and was matched 10:1 to the gMG cohort on age and index year. Cohorts were further balanced using overlap weighting on sex, race, region, and mortality-related comorbidities. Mortality was evaluated using Kaplan-Meier and Cox proportional hazards models, censoring at the end of eligibility or data.

Results 37,321 and 373,210 patients were included in the gMG and non-MG cohorts, respectively. Post-weighting, the gMG and non-MG cohorts had similar demographics (mean age: 74.2-74.4 years; 47.1-47.2% males). Hypertension (gMG: 81.2%; non-MG: 76.9%) and dyslipidemia (75.8%; 74.6%) were most common comorbidities. Mean follow-up duration was 18.9 and 18.1 months in the gMG and non-MG cohorts, respectively. At 12, 24, and 36 months, survival rates between the gMG and non-MG cohorts were 85.3% vs 86.2%, 78.0% vs 79.3%, and 72.5% vs 73.9%, respectively. Across all time points, gMG patients were at 7-8% higher risk of mortality compared to non-MG patients (all p<0.001).

Conclusions Medicare beneficiaries with gMG had consistently higher mortality than those without MG. These findings highlight the need to better identify and understand drivers of excess mortality, which may provide targeted management strategies for this vulnerable population.

Authors/Disclosures
Jacqueline Pesa (Janssen) PRESENTER	Jacqueline Pesa has received personal compensation for serving as an employee of Johnson and Johnson.
Louis Jackson, PharmD (Janssen)	Dr. Jackson has received personal compensation for serving as an employee of Johnson and Johnson.
Maryia Zhdanava	Maryia Zhdanava has received personal compensation for serving as an employee of Analysis Group.
Porpong Boonmak (Analysis Group, Inc.)	Porpong Boonmak has received personal compensation for serving as an employee of Analysis Group, Inc..
hung-chieh Chen	Dr. Chen has nothing to disclose.
Mengqi Liu, PhD	No disclosure on file
Dominic Pilon (Analysis Group, Inc.)	Dominic Pilon has received personal compensation for serving as an employee of Analysis Group, Inc..
Raghav Govindarajan, MD, FAAN (HSHS St. Elizabeth Medical Group)	Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for MT pharma. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Argenx. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Catalyst. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche . Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sarepta. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Amicus. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for UCB. Dr. Govindarajan has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Alexion. Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for MT pharma . Dr. Govindarajan has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Catalyst. Dr. Govindarajan has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Argenx. Dr. Govindarajan has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Biohaven. Dr. Govindarajan has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for UCB. Dr. Govindarajan has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Takeda. Dr. Govindarajan has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Abbvie. The institution of Dr. Govindarajan has received research support from Band of Hope . The institution of Dr. Govindarajan has received research support from Alexion. Dr. Govindarajan has received publishing royalties from a publication relating to health care.

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