Costs and Health-Related Quality of Life in Patients With NMO Spectrum Disorders and MOG-Antibody-Associated Disease: CHANCENMO Study

Abstract

Background and objectives: To evaluate costs and health-related quality of life (HRQoL) of neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

Methods: In this multicenter cross-sectional study, data on consumption of medical and nonmedical resources and work ability were assessed via patient questionnaires. Costs were analyzed in Euros for 2018 from the societal perspective. HRQoL was captured by the EuroQoL Group 5 Dimension 5 Level Scale (EQ-5D-5L) questionnaire. Clinical data were retrieved from the Neuromyelitis Optica Study Group (NEMOS) database.

Results: Two hundred twelve patients (80% women, median age 50 [19-83] years, median disease duration 7 [0-43] years, median Expanded Disability Status Scale [EDSS] score 3.5 [0-8.5], 66% aquaporin-4 immunoglobulin G [IgG] positive, 22% MOG IgG positive, 12% double seronegative) were analyzed. The mean total annual per capita cost of illness accounted for €59,574 (95% CI 51,225-68,293 or US dollars [USD] 70,297, 95% CI 60,445-80,586), and the mean index value of the EQ-5D-5L was 0.693 (95% CI 0.65-0.73). The most important cost drivers were informal care costs (28% of total costs), indirect costs (23%), and drugs (16%), especially immunotherapeutics. Costs showed a positive correlation with disease severity (ρ = 0.56, 95% CI 0.45-0.65); in the EDSS score 6.5 to 8.5 subgroup, the mean annual costs were €129,687 (95% CI 101,946-160,336 or USD 153,031, 95% CI 120,296-189,196). The HRQoL revealed a negative correlation to disease severity (ρ = -0.69, 95% CI -0.76 to -0.61); in the EDSS score 6.5 to 8.5 subgroup, the EQ-5D-5L mean index value was 0.195 (95% CI 0.13-0.28). Neither antibody status nor disease duration influenced the total annual costs or HRQoL.

Discussion: These German data from the era without approved preventive immunotherapies show enormous effects of the diseases on costs and quality of life. An early and cost-effective therapy should be provided to prevent long-term disability and to preserve quality of life.

Figure 1. CHANCE^NMO-Study Cohort Categorized by Serostatus, EDSS Score, and Disease Duration

Age and disease duration are shown as median with range in years; female sex and serostatus (aquaporin-4 [AQP4]/neg/ myelin oligodendrocyte glycoprotein [MOG]) are shown as percentage. Patient subgroups were defined on the basis of serostatus, clinical disability (Expanded Disability Status Scale [EDSS] score [score is shown as median with range]), and disease duration. Category boundaries are shown above. EDSS scores for 8 patients were missing. In 1 patient, disease duration is unknown. In both cases, this had no effect on the representativeness of the group composition. IPND = International Panel for NMO Diagnosis; MOG(AD) = MOG immunoglobulin G (IgG) antibody (associated disease); neg = patients with AQP4 and MOG-antibody–negative NMOSD; NMOSD = neuromyelitis optica spectrum disorders.

Figure 2. Mean Annual Costs per Patient Stratified by Disease Severity and Serostatus

Mean total annual costs (2018 Euros) per patient per year of the entire study population and categorized according to disease severity groups (A) and serostatus (B). AQP4 = aquaporin-4; EDSS = Expanded Disability Status Scale; IPND = International Panel for NMO Diagnosis; MOGAD = myelin oligodendrocyte glycoprotein antibody-associated disease; NMOSD = neuromyelitis optica spectrum disorders.

Figure 3. Level of Problems Experienced by Patients Stratified by Disease Severity (A) and Serostatus (B)

Patients were able to provide levels on a scale from 0 to 5 (0 = no problems, 5 = unable/ extreme problems) for each of the 5 dimensions of the EuroQoL 5 Dimensions 5 Levels questionnaire. Pain/discomfort between the aquaporin-4 (AQP4) immunoglobulin G (IgG) antibody–positive neuromyelitis optica spectrum disorder (NMOSD) group and the double seronegative NMOSD group was the only dimension that differed significantly (p = 0.009). EDSS = Expanded Disability Status Scale; IPND = International Panel for NMO Diagnosis; MOGAD = myelin oligodendrocyte glycoprotein IgG antibody–positive disease.