Fibrosing interstitial lung diseases (ILDs), with idiopathic pulmonary fibrosis being the most common form, primarily affect older individuals and have a poor prognosis, with a median survival of 3 to 5 years. While antifibrotic treatments such as nintedanib and pirfenidone can slow disease progression, their efficacy is often limited by side effects, particularly in elderly patients. A comprehensive patient assessment, including evaluations of frailty and sarcopenia, could optimize care by identifying those at risk for poor outcomes or poor treatment tolerance. Frailty, characterized by reduced physiological reserves, and sarcopenia, defined as a loss of muscle mass and strength, are both associated with increased mortality and morbidity risks. Although their individual impacts on fibrosing ILDs have been documented, the combined effect of these two syndromes on patient prognosis remains unexplored, highlighting the need for further studies to guide therapeutic decision-making.

Frailty and sarcopenia are two distinct entities, each capable of worsening patient mortality and morbidity. Their association has been studied in the general population in a cohort of over 2,000 individuals aged 70 to 85 years (34816568). The prevalence of sarcopenia among frail participants was 40%. The characteristics and risks faced by patients who were both frail and sarcopenic differed from those who were only sarcopenic or only frail.

No study has evaluated the prognostic impact of the combined presence of sarcopenia and frailty on the outcomes of patients with fibrosing ILDs.

Inclusion Criteria:

• Patient with fibrosing ILD according to the ATS/ERS/JRS/ALAT 2022 criteria.
• Patient aged ≥ 65 years.
• Outpatient consultation (scheduled appointment in an outpatient clinic, day hospital, or weekly hospital stay).
• French-speaking patient.
• Patient who has received an information sheet explaining the study and has not expressed opposition to participating in this research.

Exclusion Criteria:

• Patient under legal guardianship, curatorship, or judicial protection.
• Cognitive disorders limiting the use of questionnaires.
• Patient with a CT scan showing an early usual interstitial pneumonia (UIP) pattern according to the ATS/ERS/JRS/ALAT 2022 classification.

The study population will consist of older adults who are incident cases of patients referred to Nantes University Hospital for the evaluation of fibrosing ILD