Epidemiology, Patient Characteristics, Real-World Treatment Patterns, and Healthcare Utilization and Spending for Patients with Multifocal Motor Neuropathy: A US Claims-Based Analysis.

Background: Multifocal motor neuropathy (MMN) is a rare, progressive neurological disease characterized by asymmetrical limb weakness. The real-world healthcare burden of MMN is not well established. Objectives: To characterize the epidemiology, diagnostic procedures, treatment patterns, healthcare resource utilization (HCRU), and healthcare spending associated with MMN in patients in the US. Methods: This retrospective, observational claims study extracted data from the Humana Healthcare Research Database, comprising US Medicare Advantage plan members. Eligible patients were aged 18-89 years, had ≥2 nondiagnostic medical claims (the first being the index date) associated with an MMN diagnosis code (January 1, 2017-June 30, 2022), and continuous enrollment for 12 months pre-index (baseline) and post-index (follow-up). Patients with amyotrophic lateral sclerosis, chronic inflammatory demyelinating neuropathy, or immunosuppressant use were excluded. Outcomes were assessed during the baseline and follow-up periods. Results: Deidentified data were extracted for 248 patients with MMN. Median (Q1, Q3) age at index was 70.0 (62.0, 77.0) years; most patients were male (53.6%) and White (78.2%). Diagnostic procedures included (baseline/follow-up periods) spinal magnetic resonance imaging (21.4%/18.1%), nerve conduction studies (19.8%/14.5%), and electromyography (17.7%/15.3%). Anticonvulsants, pain medications, corticosteroids, and central muscle relaxants were the most commonly used medications. Overall, 5.2% of patients had intravenous immunoglobulin (IVIG) during follow-up. Mean (standard deviation [SD]) time from index to IVIG initiation was 63.1 (52.2) days, with 6.5 (5.4) administrations, 28.7 (22.9) days between administrations, and 147.5 (133.9) days of total treatment. For all-cause HCRU, 23.8% of patients had ≥1 inpatient stay in the baseline period, with mean (SD) length of stay of 12.7 (14.5) days; during follow-up, 27.8% of patients had ≥1 inpatient stay (length of stay, 13.4 [16.2] days). During the baseline/follow-up periods, 43.1%/46.8% of patients had ≥1 emergency department visit, and 18.5%/28.6% used telehealth services. Median all-cause spending (baseline/follow-up) was Discussion: Further studies are needed to enhance our understanding of the real-world diagnostic and treatment patterns associated with MMN and to determine long-term clinical outcomes. Conclusion: These real-world data highlighted the considerable burden associated with MMN on the healthcare system and patients.