Total Economic Impact of Anti-Aquaporin-4 Antibody-Positive Neuromyelitis Optica Spectrum Disorder

INTRODUCTION: Economic impact data for anti-aquaporin-4 antibody-positive (AQP4-Ab+) neuromyelitis optica spectrum disorder (NMOSD) are generally limited to direct medical patient costs and exclude indirect, nonmedical, and uncovered healthcare patient and caregiver costs. Here, we estimated the total economic impact of AQP4-Ab+ NMOSD in 2024 on US patients and caregivers. METHODS: This study consisted of two portions: an independent, electronically administered survey to capture indirect, nonmedical, and uncovered healthcare costs of AQP4-Ab+ NMOSD from 2023 to patients and caregivers (adjusted for inflation to 2024 dollars); and a retrospective, matched cohort claims analysis to estimate excess direct medical costs of AQP4-Ab+ NMOSD in 2024 to patients. Adults living in the USA or its territories were eligible. Annual costs for patients were calculated as the sum of weighted average indirect, nonmedical, uncovered healthcare, and excess direct costs, multiplied by the US prevalence of AQP4-Ab+ NMOSD. Annual cost for caregivers was calculated as the sum of unweighted average indirect, nonmedical, and uncovered healthcare costs, multiplied by the estimated prevalence of patients with AQP4-Ab+ NMOSD with a caregiver. RESULTS: Of 258 respondents, 209 were patients (female, 76%; mean ± SD age, 45.1 ± 12.6 years; 44% reported a relapse in 2023; 53% had an informal caregiver) and 49 were caregivers (female, 57%; mean ± SD age, 42.1 ± 13.6 years). Estimated total economic impact of AQP4-Ab+ NMOSD in 2024 dollars was $1.06 billion (excess direct medical costs, $574.2 million [54%]; patient indirect, nonmedical, and uncovered healthcare costs, $315.3 million [30%]; caregiver indirect, nonmedical, and uncovered healthcare costs, $171.5 million [16%]). Average annual indirect, nonmedical, and uncovered healthcare costs were $51,513/patient and $54,036/caregiver. CONCLUSION: Indirect, nonmedical, and uncovered healthcare costs comprise approximately half the total economic impact of AQP4-Ab+ NMOSD. These results show the importance of treating patients with optimal therapies to reduce the burden on patients and caregivers. Graphical Abstract is available with this article.