Incidence of acute exacerbation and its related factors among chronic obstructive pulmonary disease patients aged 40 years and older in China

Background: Acute exacerbation of chronic obstructive pulmonary disease (COPD) (AECOPD) represents a pivotal event in the clinical course of COPD and contributes substantially to disease progression and healthcare burden. This study examined the incidence and demographic distribution of AECOPD among Chinese COPD patients aged ≥40 years and evaluated factors associated with its occurrence, providing population-based evidence to inform community prevention, standardized treatment, rehabilitation, and health management strategies. Methods: Data were derived from the Chinese Chronic Obstructive Pulmonary Disease Surveillance (2019-2020), a nationwide cross-sectional survey conducted in 125 surveillance counties (districts) across 31 provinces, autonomous regions, and municipalities in China. Using a multistage stratified cluster random sampling design, residents aged ≥40 years were enrolled. Participants completed standardized questionnaires, physical measurements, and pre- and post-bronchodilator spirometry administered by trained investigators. COPD was defined as a post-bronchodilator forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC)