Protocol of china chronic cough registry: a multicentre, prospective, observational study

Chronic cough is a common clinical problem with complex aetiologies, often resulting in misdiagnosis, impaired quality of life and increased healthcare burden. Despite the large number of affected patients in China, nationwide multicentre data on the clinical characteristics and outcomes of chronic cough remain lacking. The C hina CH ronic C O ugh Reg I st R y (C-CHOIR) was established to develop a national clinical database and biobank for chronic cough. This is the first national, multicentre, prospective real-world registry of chronic cough in China. 6000 adult patients with cough lasting >8 weeks and no significant abnormalities on chest imaging will be recruited from 32 centres through a unified online platform. Data collection includes demographic characteristics, cough features, questionnaire assessments, laboratory findings, aetiological diagnosis and treatment information. Follow-up will be conducted within 3 months after baseline and annually for at least 2 years. Changes in cough, treatment response, questionnaire scores and any revised diagnoses will be recorded during follow-up. Biological samples, including blood cells, serum, sputum cells, sputum supernatant, urine and bronchial mucosal biopsy specimens, will be collected from a subset of patients, particularly those with refractory chronic cough, at baseline and at the first annual follow-up. This cohort is expected to define the real-world profile of chronic cough in China, identify clinically meaningful phenotypes and endotypes, and provide insights into underlying mechanisms. It will also serve as a platform for clinical research, and trials of novel therapies. Ultimately, the registry is expected to standardise management and promote the development of chronic cough subspecialty in China.