Characteristics and healthcare utilization of patients with myasthenia gravis exacerbation

Abstract

Purpose: This retrospective cohort study describes the characteristics of patients with myasthenia gravis (MG) who developed exacerbations (MG-E) and compares their healthcare utilization (HRU) to patients who did not experience exacerbations (MG-O).

Method: De-identified data from patients who had ≥2 MG-related diagnostic code submissions were extracted from the National Veterans Affairs Health Care Network electronic health records between 1999 and 2022. Descriptive statistics, Kaplan-Meier analysis, and per-patient per-year (PPPY) HRU were used to compare the two patient groups.

Results: About 34 % (3603/10,718) of patients with MG developed exacerbations over a median follow-up of 6.8 years. Approximately 52 % of the MG-E cohort had 3 or more exacerbations over the study period, averaging 1.34 (SD 2.50) exacerbations per year. The MG-E cohort had a higher incidence of early-onset MG (7.72 % vs. 4.05 %; p < 0.0001) and higher mean Charlson Comorbidity Index scores before a diagnosis of MG (0.86 vs. 0.59; p < 0.0001). Relative to patients of other racial groups with MG-E, Hispanic and African Americans had higher cumulative incidence of exacerbations over time (p < 0.0001). Additionally, MG-E patients were five times more likely to be intubated compared to MG-O patients (p < 0.0001). Increased PPPY HRU was observed in patients with MG-E compared to patients with MG-O (outpatient visit: 25.05 vs. 14.08; inpatient admission: 0.47 vs. 0.14; ED visit: 0.69 vs. 0.26; ICU stay: 0.08 vs. 0.02, respectively; p < 0.001).

Conclusion: Approximately one-third of patients diagnosed with MG experienced exacerbations, with higher incidences seen among Hispanic and African Americans. MG-E was associated with higher HRU and a higher intubation risk.

Keywords: Economic burden; Exacerbation; Healthcare resource utilization; Myasthenia gravis; Myasthenic crisis; Racial and ethnic difference.