Socioeconomic burden of AQP4-antibody seropositive NMOSD: a nationwide registry-based study.

Abstract

Background: AQP4-antibody seropositive (AQP4-Ab+) neuromyelitis optica spectrum disorder (NMOSD) may cause reduced work capability due to disability. Here, we evaluated the socioeconomic status of patients with AQP4-Ab+NMOSD in off-label therapy era compared with the general population.

Methods: A longitudinal nationwide population-based study including all Danish patients with AQP4-Ab+NMOSD and matched controls from the general population. The cohort was linked to other Danish nationwide population-based databases. The study period was from 1992 to 2021. The main outcomes were loss of income from salary, limited work capability, disability pension and civil status. The longitudinal risks of outcomes were presented in cumulative incidence curves. Fisher's exact test, χ² test or Wilcoxon test were applied for comparison.

Results: We included 65 patients with a median follow-up of 8.6 years. Annual income declined significantly after disease onset (index year) compared with the general population. One year after the index year, the median annual income in 2015-indexed Euro for patients averaged 13 285 (IQR: 139 to 36 336) versus controls 33 035 (IQR: 6870 to 45 978); p=0.04. Five years postindex year, the average income for patients further dropped to 276 (IQR: 0 to 23 691) versus controls 22 141 (IQR: 0 to 42 986); p=0.03. At the end of follow-up, significantly higher proportion of patients were either in 'flexjob' (36.9% patients vs 14% controls, p<0.00) or receiving disability pension (16.9% patients vs 4.3% controls, p<0.00).

Conclusions: The socioeconomic status of patients with AQP4-Ab+NMOSD deteriorates rapidly following disease onset. A substantial proportion of these patients lose their work capacity leading to increased financial burden on both their families and society.