[Performance of pulmonary function test in people aged 40 years and above in China, 2019-2020]

Objective: To understand the performance of pulmonary function tests in people aged ≥40 years and its changes in China, and provide evidence for the evaluation of the effect of chronic obstructive pulmonary disease (COPD) prevention and control in China. Methods: The subjects of the survey were from COPD surveillance during 2014-2015 and during 2019-2020, which covered 31 provinces (autonomous regions and municipalities) in China. The survey used multi-stage stratified cluster random sampling method, the trained investigators conducted face-to-face interview to know whether subjects had previous pulmonary function testing or not. Complex sampling weighting was used to estimate the rate of pulmonary function testing in people aged ≥40 years, and the pulmonary function testing rates of the two COPD surveillance periods were compared. Results: A total of 148 427 persons were included in the analysis, including 74 591 persons during 2014-2015 and 73 836 persons during 2019-2020. In 2019-2020, the pulmonary function testing rate in Chinese residents aged ≥40 years was 6.7% (95%CI: 5.2%-8.2%), the rate in men (8.1%, 95%CI: 6.7%-9.6%) was higher than that in women (5.4%, 95%CI: 3.7%- 7.0%), and the rate in urban residents (8.3%, 95%CI: 6.1%-10.5%) was higher than that in rural residents (4.4%, 95%CI: 3.8%-5.1%). The rate of pulmonary function testing increased with the increase of education level. During 2019-2020, the residents with history of chronic respiratory diseases had the highest rate of pulmonary function testing (21.2%, 95%CI: 16.8%-25.7%), followed by the residents with respiratory symptoms (15.1%, 95%CI: 11.8%-18.4%) , the pulmonary function testing rate in those who knew the name of chronic respiratory disease was higher than that in those who did not knew the name of respiratory disease, and the pulmonary function testing rate in former smokers was higher than that in current smokers and non-smokers. Those exposed to occupational dust and/or harmful gases had a higher rate of pulmonary function testing compared with those who were not exposed, and those who used polluted fuels indoors had a lower rate of pulmonary function testing than those who did not use polluted fuels indoors (all P<0.05). Compared with 2014-2015, the pulmonary function testing rate in residents aged ≥40 years in China increased by 1.9 percentage points during 2019-2020, and the rate of pulmonary function testing in groups with different characteristics all increased, and the rates of pulmonary function testing increased by 7.4 percentage points and 7.1 percentage points in residents with respiratory symptoms and in those with history of chronic respiratory diseases (all P<0.05). Conclusions: Compared with 2014-2015, the rate of pulmonary function testing increased in China during 2019-2020 and the increase in residents with history of chronic respiratory diseases and respiratory symptoms was relatively obvious, but the overall pulmonary function testing rate was still at a low level. Effective measures should be taken to further increase the rate of pulmonary function testing.