Quantifying the relationship between disability progression and quality of life in patients treated for NMOSD: Insights from the SAkura studies

Mult Scler Relat Disord. 2022 Jan;57:103332. doi: 10.1016/j.msard.2021.103332. Epub 2021 Oct 15.


Background: To date, no specific scales have been developed to explore the impact of neuromyelitis optica spectrum disorder (NMOSD)-related disability on quality of life (QoL). The Expanded Disability Status Scale (EDSS) and the EuroQol 5-dimensions (EQ-5D) have been used to assess disability and QoL, respectively, in patients with NMOSD. However, there is limited evidence surrounding their use in this condition. We compared EDSS and EQ-5D data across two clinical trials to quantify the relationship between disability and QoL in patients with NMOSD.

Methods: SAkuraSky (NCT02028884) and SAkuraStar (NCT02073279) were Phase 3, multicenter, randomized, international, double-blind, placebo-controlled, parallel-assignment studies of satralizumab, administered in combination with baseline immunosuppressants (SAkuraSky) or as monotherapy (SAkuraStar). EDSS and EQ-5D were assessed at baseline and at 24-week intervals thereafter. The relationship between disability and QoL was assessed by estimating EQ-5D utilities (UK tariff) for each incremental EDSS category. A repeated-measures linear model was used to regress health utilities on EDSS score-derived health states.

Results: Overall, 176 patients underwent at least one EDSS assessment and completed an EQ-5D survey and were included in this analysis. There was a clear association between mean EQ-5D score and EDSS score, with decreases in QoL being observed at each incremental increase in disability. The relationship between EDSS and EQ-5D score remained consistent across the different treatment groups.

Conclusions: These results, generated from high-quality clinical trial data, demonstrated a strong and consistent relationship between disability and QoL in patients with NMOSD.

Keywords: Association; EDSS; EQ-5D; NMO; Neuromyelitis optica spectrum disorder.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Disabled Persons*
  • Humans
  • Immunosuppressive Agents
  • Neuromyelitis Optica* / drug therapy
  • Quality of Life
  • Surveys and Questionnaires


  • Immunosuppressive Agents