Disability and caregiver dependency precedes loss of ambulation in Friedreich ataxia: loss of independence in real-world data from medical claims

Topic:

Clinical Management

Poster Number: P177

Author(s):

Shakti V. Nayar, MD, Medstar Georgetown University Hospital, Sheng-Han Kuo, PhD, Columbia University Medical Center, New York, NY, USA, Boyang Bian, PhD, Biogen, Cambridge, MA, Sarah M England, PhD, Biogen, Cambridge, MA, Daniel Gomes, Voxanalytica, San Francisco, CA, James McKay, PhD, Biogen, Inc., 225 Binney St, Cambridge, MA, US, Tony Wang, PhD, Voxanalytica, San Francisco, CA, Robin L. Avila, PhD, Biogen, Inc., Cambridge, Massachusetts, USA, Pravin Khemani, MD, Swedish Neuroscience Specialists - Movement Disorders, Seattle WA

Background: Friedreich ataxia (FA) is a rare genetic neurodegenerative disorder leading to severely impaired muscle coordination and multi-systemic complications. Previous studies have evaluated the progression of FA in relation to loss of ambulation (LoA) as an important milestone in natural history studies. However, there are no studies evaluating loss of independence (LoI)—incorporating reliance on others for personal care, need for in-home assistance and continuous supervision, and functional decline, in addition to LoA—based on real-world data from medical claims, providing a comprehensive view of the disease journey.

Objectives: Using medical claims data, we assessed and compared age at LoA and LoI in patient subgroups stratified by age at FA diagnosis.

Methods: We conducted a retrospective study based on de-identified claims data linked to mortality data covering October 2015 to March 2024. We stratified the cohort based on age at FA diagnosis: 0-7, 8-14, 15-24, and 25-39 years. We evaluated and compared median age at LoA alone and median age at LoI, stratified by age group. LoI was defined as first appearance of any ICD or HCPCS codes for (1) LoA, (2) care provider reliance for personal care, (3) continuous supervision or other assistance, and (4) Medicare eligibility under age 65 years due to disability.

Results: The cohort included 927 patients with FA. The median (IQR) age at FA diagnosis was 4.0 years (2.0-6.0; n=129), 11.0 years (10.0-13.0; n=225), 19.0 years (16.0-22.0; n=261), and 32.0 years (28.0-35.3; n=312) for patients aged 0-7, 8-14, 15-24, and 25-39 years at diagnosis, respectively. The median age at LoA was 12.3, 16.8, 27.3, and 37.7 years, while for LoI it was between 6 months and 4 years earlier at 11.7, 16.3, 24.7, and 33.6 years for patients aged 0-7, 8-14, 15-24, and 25-39 years at diagnosis, respectively.

Conclusions: These data demonstrate LoI precedes LoA by up to 4 years, creating tremendous caregiver burden in these years, which has not been previously appreciated. Our study is limited by the retrospective nature and is subject to coding preferences of each provider but provides an estimate of the age at which patients with FA lose independence due to care partner dependency, disability, or LoA.