Clinical characteristics of and risk factors for small airway dysfunction detected by impulse oscillometry

•This cross-sectional study investigated impulse oscillometry (IOS)-defined small airway dysfunction (SAD) in a large community-based population.•Individuals with IOS-SAD had poor lung function, high airway resistance, and more emphysema and gas trapping than those without IOS-SAD.•Risk factors for IOS-SAD were older age, high BMI, smoking history, passive smoking, low education, childhood cough, and asthma.