COPD Mortality Falls in China, Yet High Burden Persists in Underdeveloped Regions

Chronic obstructive pulmonary disease (COPD)–associated mortality substantially decreased from 2014 to 2021 in China, but the disease burden remains high in underdeveloped regions, according to a study published in China CDC Weekly.¹

COPD, primarily caused by exposure to air pollution and smoking, often increases the risk of other chronic events. Older adults are the most susceptible population due to age-related lung function decline. Because of the accelerating pace of aging and the large number of active smokers, China unsurprisingly has a substantial COPD burden.

Due to this growing burden, the researchers explained that it is "crucial" to assess the latest COPD-associated mortality patterns to refine management and prevention strategies. Additionally, they noted that understanding COPD’s comorbidity patterns is “essential” since it frequently coexists with other chronic conditions.

Despite this, the researchers found that most mortality estimates rely on the underlying cause of death, which may not accurately reflect the full scope of COPD-associated mortality. Consequently, they aimed to investigate the regional distribution and temporal trends of COPD-associated mortality in China between 2014 and 2021.

Chronic obstructive pulmonary disease (COPD) burden remains high in underdeveloped regions of China despite a decline in related deaths. | Image Credit: vegefox.com - stock.adobe.com

Using nationally representative data from the National Mortality Surveillance System (NMSS), the researchers estimated COPD-associated mortality from 2014 to 2021 and analyzed other major causes of death, like other respiratory events and cardiovascular diseases. NMSS covers 605 surveillance points across 31 provincial-level administrative divisions and incorporates both in- and out-of-hospital deaths.² It encompasses 323.8 million people, or 24.3% of China’s population, with national and provincial representativeness.

Stratified by region, sex, and residence, the researchers calculated the age-standardized mortality rates (ASMRs) using the direct standardization method, with the 2020 China census as the reference population.¹ Also, they used joinpoint regression to estimate the average annual percentage change (AAPC).

There was a general downward trend in COPD-related mortality from 2014 to 2021 as the absolute number of deaths decreased from 180,330 to 149,612. Therefore, the ASMR associated with COPD decreased from 91.85 to 45.90 per 100,000 people (AAPC, –9.4%; 95% CI, –10.3 to –8.4).

The researchers found that males (AAPC, –8.0%; 95% CI, –9.2 to –6.8) had higher COPD-associated mortality and a milder decrease than females (AAPC, –11.2%; 95% CI, –11.9 to –10.4). Additionally, the eastern region, which had the lowest COPD burden, showed a sharp decline during the study period (AAPC, –10.7%; 95% CI, –11.5 to –9.9), followed by the central (AAPC, –9.9%; 95% CI, –10.9 to –8.9) and western (AAPC, –7.7; 95% CI, –10.6 to –4.7) regions.

Also, COPD-associated mortality was higher in rural areas (ASMR, 54.83 per 100,000) than in urban areas (ASMR, 33.75 per 100,000). Therefore, compared with rural areas (AAPC, –8.3%; 95% CI, –9.1 to –7.4), urban areas (AAPC, –10.9%; 95% CI, –12.3 to –9.5) presented a more substantial drop in COPD-associated mortality numbers.

Overall, COPD was the most common underlying cause of death during the study period, accounting for 92.87% of all deaths. However, among all deaths with COPD as the underlying cause of death, the leading contributory cause of death was pulmonary heart disease and diseases of pulmonary circulation, with 0.9 million deaths (26.79% of all COPD deaths). Other respiratory diseases ranked second, with a proportion of 4.87% of all COPD deaths.

Lastly, the researchers acknowledged their limitations, one being that death certificates only list injuries, diseases, and complications directly causing death. Therefore, they do not account for all pre-existing conditions. However, the researchers remained confident in their findings and used them to suggest future actions.

“...COPD is still a severe public health issue in China, and health care resources may not be evenly distributed," the authors concluded. "Therefore, public health officials should prioritize a region-specific strategy for the management and prevention of COPD to alleviate the burden of disease.”

References

1. Zhou Z, Wang L, Zhou M, Yin P. Chronic obstructive pulmonary disease-associated mortality - China, 2014-2021. China CDC Wkly. 2024;6(43):1105-1110. doi:10.46234/ccdcw2024.226
2. Liu S, Wu X, Lopez AD, et al. An integrated national mortality surveillance system for death registration and mortality surveillance, China. Bull World Health Organ. 2016;94(1):46-57. doi:10.2471/BLT.15.153148