Duchenne muscular dystrophy (DMD) is a chronic neuromuscular disorder affecting approximately 150 to 200 newborns annually, predominantly males, and is characterized by progressive muscle atrophy and weakness due to a complete absence of dystrophin. DMD presents a severe phenotype, with life expectancy typically extending into the third decade. Data on healthcare utilization and associated costs for DMD patients, particularly within the French healthcare context, remain limited. The EPARDYS study aims to examine the care pathways of these patients using data from the Banque Nationale des Données Maladies Rares (BNDMR) and the Système National des Données de Santé (SNDS), enabling a detailed characterization of patient demographics, healthcare utilization patterns, and associated costs. However, only direct costs eligible for reimbursement under the Affection Longue Durée (ALD 100%) scheme can be evaluated. Additional resources are consumed by DMD patients, particularly for medical care that falls outside the scope of reimbursement. Furthermore, the high level of dependency in these patients may lead to the need for home adaptations or other expenditures outside the healthcare domain but linked to the disease. Informal caregiving also plays a significant role. These additional family-incurred costs must be considered. The CouDuMyo study will aim to estimate all relevant cost components from a societal perspective, considering both minors and adults, whether they attend school or work. The medico-social aspect of care, along with the collection of data on aids and benefits received, will offer insights into the nature of the support available to families in France. The knowledge gained regarding non-reimbursable, disease-related costs according to patient characteristics will provide a comprehensive view of the financial burden borne by patients and their caregivers. This assessment is particularly relevant in the context of emerging therapies, which may reduce these associated costs. The main objective will be to describe the resource utilization associated with DMD care that is not eligible for reimbursement, including direct medical costs not covered, medico-social expenses, direct non-medical costs, and indirect costs.