Dynamic changes in patient admission and their disabilities in multiple sclerosis and neuromyelitis optica: A Japanese nationwide administrative data study

Background: The real-world data evidences how establishment of neuromyelitis optica (NMO) disease concept and development disease modifying therapy affect the patients with multiple sclerosis (MS) and NMO are lacking. The aim of this study is to clarify the diachronic trend of the severity and admissions of patients with MS and NMO. Methods: We retrospectively investigated the trends in admissions, treatments, and disabilities in the patients with MS and NMO using the Japanese administrative data between 2012 and 2017. Results: We analyzed acute stage 9545 and 2035 admissions in each 6100 MS and 1555 NMO patients. The annual number of admission in MS significantly decreased in 6 years; however, those in NMO consistently increased. The patient proportion with lower disability was significantly increased in MS and NMO. These trends were especially observed in patients admitted to centralized hospitals with more active treatments, such as second-line disease modifying therapy for MS and plasmapheresis for NMO. Patients with NMO using DMT for MS diminished in 6 years. Conclusion: A gradual improvement of disability in patients with MS and NMO was observed, probably due to advanced treatments, increased NMO awareness, and decreased misdiagnosis, which seems to be the key for better prognosis in MS and NMO.