OBJECTIVES: Friedreich Ataxia (FA) is a progressive and systemic neurologic movement disorder, characterized by worsening ataxia, scoliosis, and loss of ambulation (LOA). This study aimed to characterize the age at LOA among a cohort of patients with FA, using retrospective United States (US) claims data.

METHODS: The US Merative MarketScan Commercial database from Aug 2010 to Sept 2020 was used. All incident patients ≤24 years of age were identified. Incidence was defined with an 18-month washout period. Included patients were followed up for 12 months. This 30-month period was used to observe LOA by age at FA diagnosis, through the presence of ≥1 LOA diagnosis or claim for mobility aid.

RESULTS: Seventy-seven patients with FA were diagnosed before 24 years of age (43 [56%] were diagnosed <16 years and 34 [44%] between 16-24 years). Of these, 42 (55%) had LOA captured within this 30-month period, and most patients were identified through their use of manual wheelchairs (83%). Among these 42 patients, the majority (57%) had LOA <16 years, with an overall mean (standard deviation [SD]) age at LOA of 15.0 (5.6) years. When stratified by age, patients who were diagnosed with FA <16 years (10.9 [4.0] years), and were observed to have LOA (n=19), had LOA at 10.3 (4.3) years; whereas those diagnosed later (16-24 years; n=23; 20.2 [2.7] years at the time of FA diagnosis) had LOA at 18.9 (3.0) years on average.

CONCLUSIONS: In this cross-sectional analysis, most patients who were diagnosed with FA before the ages of 24 years experienced LOA and wheelchair use before the age of 16 years. While limitations exist in ascertainment of LOA using claims data, findings suggest that those who had earlier onset of FA also had earlier LOA.