The NEuroCOUGH Chronic Cough Registry: a protocol for a pan-European observational study.

Chronic cough is a common clinical problem which is burdensome for patients and can be difficult to treat. Individual centres of cough expertise have been set up in countries across Europe but to date there has been no means to collate and analyse clinical data from such sites to gain a more comprehensive understanding of cough phenotypes, disease burden and the natural history of this condition. The NEw Understanding in the tReatment Of COUGH (NEuroCOUGH) registry is the first pan-European prospective observational study of adult patients referred for evaluation of chronic cough. Patients (≥18 years old) with a cough lasting more than 8 weeks with no chest radiology findings to explain the cough will be recruited. Key exclusion criteria include current or recent (<12 months) smoking, significant smoking history (≥20 pack-years) and obstructive spirometry (forced expiratory volume in 1 s/forced vital capacity ratio <0.6). The study aims to recruit 2500 patients across 13 European sites by 2026 and participants will be followed up at 12-monthly intervals for 36 months. The registry comprises comprehensive clinical, physiological and biological data on chronic cough, along with data on the impact and longitudinal outcome of chronic cough. The NEuroCOUGH registry has been established at a time of considerable advance in the field of cough. It will serve as a valuable clinical and research resource which will extend our current understanding of this difficult to treat condition. The initiative is also intended to encourage the establishment of new specialist cough clinics, thus creating much needed clinical trial infrastructure throughout Europe to ultimately improve patient care.