Health Resource Utilization (HRU) and Cost of Care (CoC) in Neuromyelitis Optica Spectrum Disorders in the US

Background: Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare autoimmune disorder of the central nervous system characterized by recurrent attacks of optic neuritis and/or myelitis (inflammation of the spinal cord). Incomplete recovery from attacks is typical, resulting in cumulative morbidity such as visual impairment and motor dysfunction.

Objectives: To provide a baseline to assess the economic impact of newly approved therapies for NMOSD treatment – Inebilizumab, Eculizumab and Satralizumab – on future Health Resource Utilization (HRU) and Cost of Care (CoC).

Methods: Patients with NMOSD were identified from the IBM Watson Health MarketScan Commercial and Medicare Supplemental Databases (2013 – 2017). Eligible patients were required to have at least ≥1 inpatient and ≥1 outpatient visits from time of diagnosis (index date) through 18 months of continuous enrollment (post index date); a highly active cohort had >2 relapses over this time frame.

Results: 1011 NMOSD patients, including 102 highly active patients, were identified, with 6% < 18 years, 20% 18-34 years and 44% 35-54 years. 74% were female. Annual per capita cost associated with NMOSD is a large component of total healthcare cost for both NMOSD patients and the highly active cohort, 42 and 65%, respectively. Annual per capita NMOSD cost of highly active patients is 3-fold that of all NMOSD patients. Inpatient and diagnostic costs (i.e., MRI/CT) were the two primary cost drivers, much higher than ER/office visits or lab costs. Cost of inpatient admissions among highly active patients was more than twice that of the total population. 23% of all NMOSD pts and 41% of highly active patients had at least one inpatient admission per year related to NMOSD. Mean length of stay was 10.2 days for all patients and 22.6 days for highly active patients. 28% of NMOSD patients and 38% of highly active patients had annual MRIs/CTs. NMOSD patients have numerous comorbidities, with hemi/paraplegia, neuropathic pain and bladder dysfunction having the highest associated costs. Cost of these comorbidities among highly active patients is 1.6 – 2.1x that of the general NMOSD population.

Conclusions: NMOSD is associated with costly acute and preventive care, disease monitoring and associated comorbidities. Highly active disease adds significant cost and resource utilization. New NMOSD indicated drugs that reduce attack frequency, hospitalization and disability accrual may positively impact HRU and lifetime CoC. Periodic studies are recommended to monitor this impact.