The natural history of severe chronic obstructive pulmonary disease: The SPOCCAT study protocol

Introduction: Patients with severe chronic obstructive pulmonary disease (COPD) are often underrepresented in cohorts, creating uncertainty about the natural history and prognostic factors of this subgroup. Our goal was to describe the SPOCCAT (Severe COPD: Prospective Observational study of COPD in Catalonia) study protocol.Materials and Methods: SPOCCAT is a non-interventional, multicenter, prospective cohort study of patients with severe COPD (FEV1 % predicted < 50%). The study aims to: (1) establish a five-year prospective cohort; (2) identify demographic and clinical characteristics; (3) describe treatment patterns; (4) better understand the natural history of severe COPD, including lung function decline, exacerbation rates, and mortality; and (5) identify prognostic factors for poor outcomes.Recruitment began in January 2024, and the cohort will be followed for a minimum of five years (or until death or lung transplant) with follow-up visits every 12 months. Baseline data include demographics, laboratory analyses, comorbidities, lung function, respiratory symptoms, respiratory disease exacerbations and etiology, quality of life, physical activity, chest computed tomography, and treatment. Annual follow-up visits will assess changes in treatment, exacerbation frequency and severity, microbiological outcomes, complementary tests, and mortality. Participation requires written informed consent from all patients, with data collected in an anonymized electronic Case Report Form.Results: The results of the SPOCCAT study will provide relevant information about the characteristics, treatment, and prognostic factors of severe COPD.Conclusions: SPOCCAT has the potential to enhance understanding of severe COPD, exploring innovative aspects and establishing a robust research framework for future COPD-related projects.