Socioeconomic Factors Associated with ≥2-year Delayed Diagnosis of Neuromyelitis Optica Spectrum Disorder (NMOSD) in the United States.

OBJECTIVE

The objective of this study is to explore the impact of socioeconomic factors on risk of ≥2-year delayed diagnosis of NMOSD.

BACKGROUND

Consequences of delayed diagnosis in NMOSD could be as severe as complete blindness or quadriplegia. Female sex and African ancestry are risk factors for delayed diagnosis across many disease states in the US. Patients with NMOSD are disproportionately represented by women of African descent suggesting that there may be socioeconomic barriers to timely diagnosis.

DESIGN/METHODS: This retrospective cohort study of patients with NMOSD used a closed claims database linked with socioeconomic market research and American Community Survey data at the zip-9 level. Patients were included if they had at least 2 NMOSD claims ≥30 days apart between January 2018 and December 2021. Symptom onset was defined as the first claim of associated NMOSD symptoms up to 15 years prior to diagnosis. ≥2-year delayed diagnosis was defined as diagnosis at or after 2 years of symptom onset. The conceptual causal framework was illustrated with a directed acyclic graph. Multivariable regression models were used to estimate associations of patient characteristics and several socioeconomic variables with risk of ≥2-year delayed NMOSD diagnosis.

RESULTS

In multivariable regression analysis, factors associated with ≥2-year delayed diagnosis were female sex (OR 1.44; 95%CI 1.07-1.95) and Managed Medicaid coverage (OR 1.45; 95%CI 1.11-1.89). Factors associated with diagnosis in <2 years included age≤45 (OR 1.43; 95%CI 1.06-1.94), moderate and severe comorbidity [(Moderate OR 1.62, 95%CI 1.13-2.33), (Severe OR 1.56; 95%CI 1.04-2.35)], and western US regions (OR 1.56; 95%CI 1.12-2.16). There was no impact of other socioeconomic factors on ≥2-year delayed diagnosis. However, patient-level data on race/ethnicity was not available.

CONCLUSIONS

This study demonstrated that otherwise healthy, female, Managed Medicaid beneficiaries, age >45 years may be at highest risk for ≥2-year delayed diagnosis of NMOSD.