Real-World Patterns of Korean Medicine and Combined Korean–Western Medicine Use in Patients with Chronic Cough: A Nationwide Cohort Study

Background Chronic cough impairs quality of life and increases healthcare utilization, yet no pharmacological treatment is formally approved. Korea’s dual healthcare system, which fully integrates Western medicine (WM) and Korean medicine (KM) under national insurance, provides a unique setting to examine real-world treatment patterns. Objective To compare KM-only and integrative KM + WM care for chronic cough and describe the use of key KM modalities and multimodal treatment combinations. Methods This retrospective cohort study analyzed nationwide claims data from the Health Insurance Review and Assessment Service (HIRA), 2011–2020. Chronic cough was defined as ≥ 56 days with ≥ 3 outpatient visits. Patients diagnosed with cough (R05) in KM institutions were included and classified into KM-only or KM + WM groups based on WM encounters within ± 30 days of the index episode. KM modalities (acupuncture, moxibustion, cupping, herbal medicine) and WM prescriptions were assessed, with comorbidities evaluated using the Charlson Comorbidity Index (CCI). Results Among 14,223 patients (mean age 58.6 years), 74.8% received KM-only care and 25.2% sought KM + WM care. Despite overall declines in KM utilization, the proportion of chronic cough patients among KM outpatients increased from 1.15% in 2011 to 2.76% in 2020. The KM + WM group had higher comorbidity burden (CCI ≥ 1: 43.7% vs. 32.8%) and more GERD (50.1% vs. 31.3%), allergic rhinitis (51.0% vs. 30.1%), and asthma (26.8% vs. 14.4%). Acupuncture was nearly universal (98.6%; mean 19.8 sessions), with cupping (59.3%) and hot–cold meridian therapy (42.9%) as common adjuncts. Herbal use was led by Samso-eum (35.0%) and So-cheong-ryong-tang (23.3%), whereas GERD-targeted formulas were rarely prescribed (Ojeok-san 3.3%, Saengmaek-san 2.7%). Conclusions KM was the primary treatment option for chronic cough in Korea, while integrative KM + WM care was more common in patients with greater comorbidities. Acupuncture-centered multimodal approaches predominated, but the mismatch between GERD prevalence and GERD-targeted prescriptions highlights the need for standardized, evidence-based integrative guidelines. Findings reflect patients who initially sought KM care and should be interpreted within this context when informing policy and clinical practice.