Prevalence and associated factors of COPD in primary care settings: a cross-sectional study in Chongqing, China

We aimed to estimate the population-standardized prevalence, absolute number of cases, and life-course factors associated with chronic obstructive pulmonary disease (COPD) in primary care settings of Chongqing, China. This cross-sectional study was conducted from February to October 2025 across 17 survey sites within 12 districts and counties in Chongqing. Permanent residents aged ≥ 20 years were recruited by convenience sampling at the participating facilities. Trained interviewers collected data on sociodemographics, lifestyle, environmental factors, and medical history using a standardized face-to-face questionnaire. Spirometry was performed according to the ATS/ERS 2019 technical standards. COPD was defined utilizing the GOLD 2025 guidelines (post-bronchodilator FEV 1 /FVC ratio < 0.70) alongside strictly verified medical records. The prevalence was standardized according to the age and sex distribution of the Chongqing population. Among the 4,914 adults aged ≥ 20 years, 1,371 met the case definition (crude prevalence 27.90%). After age - sex standardization to the 2020 Chongqing population structure, the standardized prevalence of COPD among adults aged ≥ 40 years was 26.76% (95% CI 25.44–28.12), which was significantly higher in men (36.93%, 95% CI 34.98–38.92) than in women (14.35%, 95% CI 12.83–16.03). GOLD staging was available for 1,020 of the 1,371 COPD cases (74.4%); Among the staged cases, the majority in both sexes were GOLD stage II (men 61.95% [503/812]; women 64.90% [135/208]). Multivariable analyses revealed that older age, male sex, lower education and income, underweight, and a history of tuberculosis were significantly associated with higher odds of COPD. Furthermore, adverse early-life factors and a family history of respiratory diseases were independently associated with the disease. Extrapolating the primary-care prevalence to the corresponding population strata suggests an estimated 3,933,463 adults aged ≥ 40 years in Chongqing have COPD (2,635,217 men and 1,298,246 women). The disease burden of COPD among adults attending primary healthcare facilities in Chongqing is substantial, with notable sex disparities in both prevalence and associated factors. The disease was associated with a constellation of factors across the life course in mutually adjusted analyses.