Trends in the Burden of COPD Attributable to Ambient PM_2.5 Exposure in China 1990-2019: An Age-Period-Cohort Analysis

Exposure to ambient particulate matter (PM_2.5) is the leading risk factor for developing chronic obstructive pulmonary disease (COPD) in China. The present study aimed to investigate the trends in COPD mortality attributable to ambient PM_2.5 exposure in China from 1990 to 2019.

Data on COPD burden attributable to ambient PM_2.5 exposure in China were extracted from the Global Burden of Disease (GBD) study 2019. The estimated annual percentage change (EAPC) was used to assess COPD mortality from 1990 to 2019. The APC model was used to analyze the temporal trends in the rate of COPD mortality attributable to ambient PM_2.5 exposure according to age, period, and cohort.

Exposure to ambient PM_2.5 contributed to 192.4 thousand deaths in 1990 and 263.6 thousand deaths in 2019. The age-standardized mortality rate (ASMR) and the age-standardized disability-adjusted life year rate (ASDR) due to ambient PM_2.5 exposure showed a gradual downward trend, the ASMR and ASDR in 2019 decreased to 16.6 per 100,000 with an EAPC of -2.82 (95% CI: -8.61 to 3.34) and 278.6 per 100,000 with an EAPC of -2.02 (95% CI: -7.85 to 4.19), compared to those in 1990, respectively. The relative risk (RR) of COPD increased with age in females, while in males, mortality significantly increased from the levels among those in the 60-64 age group to that among those in the 90-94 age group. In the period group, the RR of COPD in males remained above 1.0 from the 2000 to 2004 period, but it gradually decreased in females. The cohort effect showed an overall downward trend.

Although the ASMR and ASDR are decreasing in Chinese patients with COPD, the number of deaths due to COPD is increasing. Ambient PM_2.5 exposure is more harmful in males and older people above 60 years of age.