Clinical and functional characteristics of chronic obstructive pulmonary disease among smokers and never-smokers: a retrospective cross-sectional observational study at a specialist center in Guayaquil, Ecuador, 2023–2025
Chronic obstructive pulmonary disease (COPD) also occurs in people who have never smoked, particularly in settings where pulmonary tuberculosis and household biomass exposure remain common. We aimed to compare clinical and functional characteristics of smokers and never-smokers with established COPD and to determine wh...