Transitions Among Four Spirometric States and Subsequent Pre-Bronchodilator Airflow Obstruction: A Community Cohort Study

Purpose

To compare short-term transitions among four pre-bronchodilator spirometric states, assess subsequent airflow obstruction risk by baseline state and the distribution of these states among observed events, and examine the association between repeated isolated spirometry-defined small-airway dysfunction (sSAD) and subsequent airflow obstruction. Patients and methods: We analyzed spirometry data from three Chinese community cohorts (2019-2023). Modified Poisson regression assessed subsequent pre-bronchodilator airflow obstruction (AFO) by baseline state. Logistic models additionally adjusted for baseline FEV1/FVC. Repeated isolated sSAD was examined using bias-reduced logistic models before and after adjustment for prior FEV1/FVC values.