Evaluation of comorbidities and health care resource use among patients with highly active neuromyelitis optica

Background: Neuromyelitis optica (NMO) is characterized by unpredictable attacks on the optic nerves and spinal cord, causing accumulations of neurological disability that may lead to blindness and paralysis. We examined comorbidities and health care use among patients with highly active NMO, defined as at least two relapses within 12 months of the patient's first NMO encounter in the database. Methods: This retrospective study of a US administrative claims database compared patients with highly active NMO to matched individuals without NMO. All outcomes, including Charlson Comorbidity Index (CCI) score, hospitalizations, and emergency department visits, were measured over the 12-month period following the patient's first NMO encounter in the database. Results: A total of 1349 patients with NMO were identified. Of these, 134 had highly active NMO (80% female, mean age 45.6 years) and were matched to 670 non-NMO controls. Patients with highly active NMO had significantly greater comorbidity burden than non-NMO controls (mean CCI score: 4.1 versus 0.6; P < 0.0001) and greater proportions of hospitalization (53.7% versus 4.0%; P < 0.0001) and emergency department visits (60.5% versus 9.7%; P < 0.0001). Conclusions: High occurrence of several acute and chronic conditions and extensive health care use highlight the significant medical burden among patients with highly active NMO.