Burden of Chronic Cough and Refractory/Unexplained Chronic Cough in South Korea: A Multicenter, Observational Study (CHORUS)

PURPOSE: Refractory or unexplained chronic cough (RUCC) represents an unmet clinical need. This study aimed to explore the components constituting the disease burden in patients with RUCC by comparing clinical features, healthcare use, and patient-reported outcomes with those of chronic cough (CC) of recent onset (< 1 year). METHODS: A total of 200 individuals were prospectively enrolled from seven referral clinics in South Korea, including 100 with RUCC and 100 with CC of recent onset (< 1 year). Data were obtained through structured interviews and medical record reviews. Measures included general and cough-specific quality-of-life, mood, cough hypersensitivity symptoms, work productivity, and healthcare utilization. RESULTS: Individuals with RUCC were significantly older than those with CC (57.5 ± 15.1 vs. 48.9 ± 17.6 years) and had markedly longer cough duration (median 80 vs. 4 months). The RUCC group demonstrated higher out-of-pocket costs, more healthcare facility visits, and greater numbers of diagnostic tests and prescribed medications. However, cough-specific and general health-related quality of life scores showed no significant differences. Correlation analysis revealed comparable but stronger associations between cough-specific quality-of-life and general health outcomes in RUCC than in CC. CONCLUSION: RUCC imposes a substantial and multidimensional burden that extends beyond symptom severity. Chronicity, healthcare complexity, and psychosocial impact appear to be central features. Future evaluation tools should incorporate time and lived experience to more accurately capture the true burden of chronic cough.