Control of chronic obstructive pulmonary disease in urban populations: findings from a cross-sectional prevalence survey in Shenzhen, China

• DOI: 10.1007/s11356-021-16553-z
• Publication Date: 2021-09-22T22:05:04Z
• Authors: Le-Cai Ji; Jin-Feng Yin; Chun-Rong Lu; Hong-Yun Guan; Wei-Guo Tan; Ling-Wei Wang; Qi Jiang
• Keywords: Chronic bronchitis; Cross-sectional study

Abstract Background: The prevalence of chronic obstructive pulmonary disease (COPD) among urban populations is generally Lower than rural residents, but the disease burden is still high. Limited evidence on the patients’ characteristics has been offered to guide the control of the disease in city settings. Methods: We conducted a cross-sectional prevalence survey of COPD among residents aged ≥40 years in an emerging city Shenzhen, China. The multi-stage stratified random sampling method was applied to enroll eligible participants from September, 2018 to June, 2019. Tested by spirometry, individuals were diagnosed with COPD if the post-bronchodilator FEV1/FVC ratio was less than 0.7. Patients’ demographic and clinical characteristics, as well as estimates of the exposure to air pollutants, were included in the univariable and multivariable logistic regression models to assess the risk factors for COPD. Results: A total of 4157 individuals were invited to participate in this survey and 3591 who had available spirometry results and epidemiological data were enrolled in the final analysis. The estimated standardized prevalence of COPD among residents over 40 years old in Shenzhen was 5.92% (95% confidential intervals 4.05-8.34). Risk factors for COPD included elder age (adjusted odds ratio 1.206, 95% CI 1.120-1.299 per 10-year increase), smoking over 20 pack-years (1.968, 1.367-2.832), history of chronic bronchitis (1.733, 1.036-2.900) or asthma (4.920, 2.425-9.982), and exposure to higher annual minimum concentrations of ambient SO2 (1.156, 1.053-1.270 per 1-µg/m3 increase). Among 280 spirometry-diagnosed patients, most (221, 78.93%) patients were classified as mild COPD (GOLD stage I). The COPD assessment tests showed 24.7% (58/235) patients had severe symptoms with a total score ≥ 10, and 82.6% (194/235) were clinically symptomatic with a total score ≥ 2. Conclusions: This survey found a low prevalence of COPD in Shenzhen and most patients had mild symptoms, thus recommended screening using spirometry in primary health care to detect early-stage COPD. Increased risk from the exposure to air pollutants also indicated the urgent need for environmental improvement in city settings.