Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system that often leads to accumulation of severe disability. Patients with highly active NMOSD have a roughly 10-times higher hospital inpatient admission rate compared with patients without NMOSD. Limited data have been published on the cost of illness for patients with NMOSD, including treatment with rescue therapies (RTs) and use of health services in the emergency room (ER) and inpatient hospital settings.
To evaluate the cost of illness related to ER visits, hospitalizations and RTs in patients with NMOSD compared with controls without NMOSD (non-NMOSD) in US commercial claims databases.
This study used claims from the Truven Health MarketScan Commercial and Medicare Supplemental Databases between 2014 and 2018. Patients were identified as having NMOSD if they had ≥1 inpatient or ≥2 outpatient claims for NMO diagnosis ≥60 days apart or ≥2 claims for transverse myelitis diagnosis in combination with ≥1 claim for optic neuritis ≥6 months apart. Continuous enrollment ≥6 months before and ≥1 year after the first claim (index date) was required. Non-NMOSD controls were matched 5:1 to patients with NMOSD. Total costs of ER visits and hospitalizations in consumer price index–adjusted 2019 US dollars within 12 months post–index date were calculated for each patient.
A total of 162 patients with NMOSD (mean [SD] age, 43.3 [18] years) and 810 non-NMOSD controls (mean [SD] age, 43.3 [18] years) were evaluated. ER visits and hospitalizations for NMOSD vs non-NMOSD groups occurred in 35.8% vs 16.9% and 41.4% vs 5.1% of patients (p<0.001 for both), and mean (SD) time in hospital was 21.2 (32.7) vs 5.24 (6.46; p<0.001) days, respectively. Nearly 12% of patients with NMOSD were treated with RTs (intravenous immunoglobulin [IVIG] or plasma exchange [PLEX]) vs none for non-NMOSD controls. Mean (SD) costs per patient were $2,400 ($7,771) vs $408 ($2,579) for ER visits, $29,054 ($144,872) vs $1,521 ($10,759) for hospitalizations and $912.73 ($5,032.75) vs $0 for IVIG/PLEX for the NMOSD vs non-NMOSD groups (p<0.001 for all).
Compared with controls, patients with NMOSD had significantly longer hospital stays and higher costs associated with ER visits, hospitalizations and RTs. These results highlight the severity of NMOSD, the economic burden of illness, and the unmet need for more safe and effective treatments.