A23-23 Acute Respiratory Events Often Precede and Coincide With Diagnosis of Asthma and COPD in Primary Care

Introduction Diagnostic delays in obstructive lung diseases are common, with many patients presenting repeatedly with respiratory symptoms before diagnosis. Real-world data describing these delays in primary care is limited. We aimed to (1) count the number of respiratory visits preceding first diagnosis; (2) measure time to diagnosis from first unplanned respiratory visit and (3) understand when patients are being diagnosed relative to a respiratory exacerbation. Methods We conducted a retrospective cohort study using the Primary Care Audit, Teaching, and Research Open Network (PATRON) dataset, which captures de-identified electronic medical record data from 129 Australian general practices. Patients aged over 12 years with either; a general practitioner-coded diagnosis for asthma, COPD or Asthma-COPD Overlap Syndrome (ACOS), or a preventer inhaler prescription between 2020 and 2025 were included, contributing 242392 respiratory visits from 1 January 1995 - 3 July 2025 (n = 61812 patients). Diagnosis date was defined as the earliest general-practitioner-coded diagnosis or preventer prescription. Respiratory visits were identified by symptom-based keywords or relevant prescriptions. Exacerbations were defined as visits with prescriptions for oral corticosteroids or specified antibiotics. Diagnosis categories were not mutually exclusive; patients could contribute to more than one category where multiple diagnoses were recorded. Outcomes included days and visits to diagnosis and the proportion of diagnoses occurring within ±7-90 days of an exacerbation. Results A total of 61812 patients with obstructive lung disease were included, contributing 242392 respiratory visits. The median (IQR) time from first respiratory visit to obstructive lung disease diagnosis was 189 (0-2238) days, with 2 (1-5) respiratory visits before diagnosis. By diagnosis type, median (IQR) days to diagnosis were 93 (0-1844) for asthma, 695 (0-3619) for COPD, 977 (0-4874) for ACOS. There was also delay to preventer initiation; in the 43160 (69.8%) patients who were prescribed preventer, median of visits and days prior to prescription was 2 (1-5) and 199 (0-2282), respectively. Overall, 40.5% of diagnoses occurred within 30 days, 5.3% between 31-180 days, 4.1% between 181-364 days, and 42.2% after ≥1 year of the first respiratory presentation. Among all patients, 8.9%, 32.8%, and 40.2% were diagnosed within ±7, ±21, and ±90 days, respectively, of an exacerbation. Conclusions Acute exacerbations serve as both a diagnostic trigger for some and a missed opportunity for many others. Exacerbations frequently precede chronic airways disease diagnosis, potentially offering a diagnostic opportunity. This abstract is funded by: Charlies Foundation for Research, BIGP24-25_17