The challenges of recruiting never-smokers with chronic obstructive pulmonary disease from the large population-based Swedish CArdiopulmonary bioImage study (SCAPIS) cohort

Background A substantial proportion of individuals with COPD have never smoked, and it is implied to be more common than previously anticipated but poorly studied.Aim To describe the process of recruitment of never-smokers with COPD from a population-based cohort (n = 30 154).Methods We recruited never-smokers with COPD, aged 50–75 years, from six University Hospitals, based on: 1) post broncho-dilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) 100% of predicted (26%) or z-score ≥ −1,64 (24%). Finally, 154 never-smokers with COPD were included: 56 (36%) women, (mean) age 60 years, FEV1 84% of predicted, FEV1/FVC: 0.6, z-score: −2.2, Oxygen saturation: 97% and BMI: 26.8 kg/m2.Conclusions The challenges of a recruitment process of never-smokers with COPD were shown, including the importance of correct spirometry testing and strict inclusion criteria. Our findings highlight the importance of repeated spirometry assessments for improved accuracy in diagnosing COPD