C39-07 The Australasian Interstitial Lung Disease Registry (AILDR): Demographics, Disease Characteristics, and Transplant-free Survival Insights From a Bi-national Cohort

Abstract Rationale The Australasian Interstitial Lung Disease Registry (AILDR) was established to capture real-world longitudinal data on interstitial lung disease (ILD) across Australia and New Zealand, aiming to support high quality research, standardise diagnostic and treatment pathways, and improve patient care. We describe the registry population and review clinical outcomes across ILD subtypes. Methods Data was analysed from registry inception in May 2016 to September 2025 inclusive. Cox proportional hazards models were used to assess associations with transplant-free survival (TFS, including death or lung transplantation). Each ILD diagnosis was evaluated estimating its hazard relative to the overall cohort. Results To date, 5,114 participants have been enrolled from 23 sites across Australia and NZ. Participants had a mean age of 67.5 (SD 13) years, BMI of 29.1 (SD 5.8) kg/m2. 55.8% (n = 2853) were male, 84.5% (n = 4276) were Caucasian and 58% (n = 2692) were ever-smokers. The most prevalent diagnoses were idiopathic pulmonary fibrosis (IPF, 31%; n = 1444), connective tissue disease-ILD (CTD-ILD, 17.7%; n = 825), unclassifiable ILD (10.6%; n = 493), hypersensitivity pneumonitis (HP, 8.8%; n = 409), and sarcoidosis (6.6%; n = 307). Pulmonary function demonstrated mild impairment at baseline with an FVC% predicted of 85.1% (SD 21.4%), DLCO% predicted of 66.6% (SD 22.1%) and six-minute walk test SpO2 nadir 90.0% (SD 7.2%). Antifibrotics were prescribed in 32.6% (n = 1295), of which IPF was the majority indication (69.1%). Over a median (IQR) follow-up of 37.1 (13.1-66.4), 1290 (25.4%) have died and 134 (2.6%) have undergone lung transplant. In univariable Cox models, age, male sex, ever-smoking, lower baseline FVC% predicted and DLCO% predicted were independently associated with worse TFS. Diagnoses of IPF (HR 2.08, 95% CI 1.85 to 2.33; p 0.0001), HP (HR 1.53, 95% CI 1.28 to 1.83; p 0.0001) and unclassifiable ILD (HR 1.35, 95% CI 1.13 to 1.62; p = 0.001) were also associated with reduced TFS. Sarcoidosis (HR 0.17, 95% CI 0.11 to 0.28; p 0.0001) and CTDILD (HR 0.57, 95% CI 0.48 to 0.67; p 0.0001) had a lower risk compared to other ILD subtypes. In multivariable analyses, when adjusting for age, smoking status, gender, baseline FVC% and DLCO%, these associations remained unchanged. Conclusion The AILDR represents a large bi-national cohort, enabling meaningful assessment of ILD demographics and clinical outcomes across real-world patients. This abstract is funded by: This project was supported by the Australasian Interstitial Lung Disease Registry and the Centre of Research Excellence in Pulmonary Fibrosis, which is funded by the NHMRC (GNT1116371 and GNT2015613), anonymous philanthropy, Boehringer Ingelheim and Lung Foundation Australia.