Assessing the Economic and Quality of Life Impact of Treatment in Duchenne Muscular Dystrophy

OBJECTIVES: Loss of ambulation (LOA) in Duchenne muscular dystrophy (DMD) leads to substantial increases in costs and reduction in quality of life (QoL) for patients and caregivers, but the impact of treatments that delay LOA remains understudied.

METHODS: We developed a cost (2020 US$) and QoL calculator for direct and indirect costs and quality-adjusted life-years (QALYs) in DMD over a 13-year time-horizon in the US. Two scenarios were compared: with and without a hypothetical treatment that delayed LOA by 4 years as the patient progresses through early and late ambulatory and non-ambulatory stages. Direct costs included inpatient, outpatient, professional fees, medical equipment, and non-DMD-specific drugs; the hypothetical treatment was excluded. Indirect costs included caregiver income loss, cost of reduced QoL, loss of leisure time, informal care, non-medical costs (e.g., home reconstruction), and non-medical community services (e.g., transportation). Direct costs were estimated from DMD patients in the Milliman Consolidated Health Cost Guidelines Sources Database while indirect costs and QoL utilities were estimated from published literature. Sensitivity analyses included the hypothetical treatment in the direct costs and varied the assumption that the hypothetical drug delayed disease progression.

RESULTS: Annual direct and indirect costs for non-ambulatory patients were $63,043 and $163,738 higher, respectively, compared to ambulatory patients. The hypothetical treatment that delayed LOA by 4 years resulted in savings of $308,589 and $821,856 direct and indirect costs, respectively, over 13 years, which amounted to 62% of the total costs. Patients gained 2.1 QALYs in a period of 13 years. Findings remained robust in sensitivity analyses with cost-savings of more than 46% after including the cost of DMD treatment.

CONCLUSIONS: DMD treatments that delay LOA substantially reduce disease management costs and costs to caregivers and improve patient QoL.