Characterizing financial toxicity among people living with neuromyelitis optica spectrum disorder.

Financial toxicity (FT) and the social determinants of health (SDOH) remain underexplored in neuromyelitis optica spectrum disorder (NMOSD). To characterize FT in NMOSD and examine sociodemographic and clinical features. We conducted a convenience-sampled, cross-sectional, anonymous survey (08/2024-03/2025) of 124 U.S. adults. The COmprehensive Score for financial Toxicity (COST) was used to measure FT (lower COST = higher FT). Seventy-five percent had a COST < 25 points, consistent with FT. In multivariable analysis, a higher attack frequency was associated with a 1.20-point lower COST score (95% confidence interval [CI] -1.90, -0.50), and each one-unit increase in disability, as measured by the Patient-Determined Disease Steps, was associated with a 0.80-point lower COST (95% CI -1.40, -0.20). Non-White race was associated with a 3.50-point lower COST (95% CI -5.80, -1.20), and double-seronegative antibody status with a 2.80-point lower COST (95% CI -5.00, -0.60). Mediation analysis suggested the effects of disability and race on FT are partially attributable to income.In exploratory models with attack count as the outcome, each one-point higher COST (lower FT) was associated with a 0.043-attack decrease (95% CI -0.081, -0.005). Financial toxicity is highly prevalent in NMOSD and associated with key clinical and sociodemographic features. There is a need for comprehensive NMOSD care models that address financial strain.