Claims Data Suggest High Clinical, Economic Burden of MG Exacerbations Despite Treatment Options

Exacerbations of myasthenia gravis (MG) are associated with both clinical and economic burden, and occur despite use of treatment, show new study data published in Journal of Comparative Effectiveness Research, which suggest the pattern is seen regardless of insurance type.

Previous research has pointed to higher health care resource utilization among patients with MG, with one analysis showing that patients with the disease were 2.6 times more likely to be hospitalized and 4.5 times more likely to be admitted to an intensive care unit (ICU) compared with healthy controls.

Researchers of the current study took a deeper look at the impact of MG exacerbation on health care utilization by insurance type, as patients may have varying access to treatment and care based on coverage. The group retrospectively analyzed claims data from a commercial claims database and a Medicare database, compiling data on 9000 patients with MG. All results coming from the study were descriptive, with no statistical comparisons made.

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Over the 2-year follow-up period, 1 in 3 (34.4%) patients had at least 1 exacerbation, suggesting inconsistent responses to current treatment options for the rare, chronic autoimmune disease. Of the 3200 patients who had an exacerbation, more than half (53%) had commercial coverage and 39% were on Medicare. Due to a low patient number (N = 243), the researchers had limited data on patients with Medicaid coverage, who accounted for 8% of those who experienced an exacerbation.

The average total cost for health care utilization related to MG exacerbation ranged from approximately $26,000 to over $50,000 for patients with commercial insurance and from approximately $20,000 to $50,000 for patients with Medicare coverage. Compared with the first exacerbation episode, subsequent exacerbations were associated with lower inpatient costs but increased outpatient costs.

“This may be the result of commercial patients opting to manage subsequent MG exacerbations in an outpatient setting, perhaps owing to employment and other commitments associated with younger age,” suggested the researchers. "Relatedly, a reduction in the proportion of commercial patients requiring MG-related [emergency department] and ICU services after the first exacerbation may suggest that subsequent exacerbations were less severe or were more manageable in the outpatient setting.”

Across the patients experiencing an exacerbation throughout the study period, the most common treatment used, regardless of insurance type, was acetylcholinesterase inhibitors, consistent with current treatment guidance. Use of the treatment dropped with subsequent exacerbations. A similar pattern was seen for use of corticosteroids (CS) among commercial patients, which was also commonly used. For patients with Medicare coverage, CS use was highest between the first and second exacerbation.

Not surprisingly, uptake of intravenous immunoglobulin, used as an acute treatment, increased with recurrent exacerbations. Nonsteroidal immunosuppressive therapy was not commonly used as an add-on treatment among either group of patients, with less than 1 in 5 patients with either insurance type using the treatment between study initiation and third exacerbation.

Between the first and third exacerbation, MG-related outpatient costs increased for patients with commercial insurance and were lowest for patients with Medicare during the first exacerbation. When grouping patients by last exacerbation episode, multiple exacerbations were associated with lower MG-related costs per episode than for a single exacerbation episode among commercially insured patients. Among Medicare patients, single or multiple exacerbation episodes were associated with high MG-related costs.

“Approximately half of the cohort experienced at least 2 exacerbations during the 2-year follow-up, highlighting the need for new and effective treatment approaches that can reduce the clinical symptoms of patients with MG,” explained the researchers. “During follow-up, the average count of exacerbations per patient was lower among Medicare patients than commercial patients. This observation could be a consequence of the smaller proportion of female patients in the Medicare population, compared with the commercial population, as evidence in the literature suggests that MG may be more severe in women, including a previous study which reported a higher MG exacerbation rate for females than males.”

Although mechanisms underlying the increased disease severity observed in women are not well understood, chromosomal inactivation and hormonal fluctuations have been suggested.

Reference

Pisc J, Ting A, Skornicki M, Sinno O, Lee E. Healthcare resource utilization, costs and treatment associated with myasthenia gravis exacerbations among patients with myasthenia gravis in the USA: a retrospective analysis of claims data. J Comp Eff Res. Published online December 15, 2023. doi:10.57264/cer-2023-0108