Baseline Cohort Profile of the Korean Chronic Cough Registry: A Multicenter, Prospective, Observational Study

Purpose The Korean Chronic Cough Registry study was initiated to characterize patients with chronic cough (CC) and investigate their outcomes in real-world clinical practice. This report aims to describe the baseline cohort profile and study protocols. Methods This multicenter, prospective observational cohort study included newly referred CC patients and those already being treated for refractory or unexplained chronic cough (RUCC). Cough status was assessed using a visual analog scale, the Leicester Cough Questionnaire (LCQ), and the Cough Hypersensitivity Questionnaire (CHQ). Results A total of 610 patients (66.9% women; median age 59.0 years) were recruited from 18 centers, with 176 being RUCC patients (28.9%). The median age at CC onset was 50.1 years, and 94.4% had adult-onset CC (≥ 19 years). The median cough duration was 4 years. Compared to newly referred CC patients, RUCC patients had a longer cough duration (6.0 years vs. 3.0 years) but had fewer symptoms and signs suggesting asthma, rhinosinusitis, or gastroesophageal acid reflux disease. Subjects with RUCC had lower LCQ scores (10.3 ± 3.3 vs. 11.6 ± 3.6; P