The elderly as a population at risk of chronic obstructive pulmonary disease mortality due to ambient ozone exposure: results from the Global Burden of Disease Study 2021.

Background and objective: To provide guidance on management strategies for chronic obstructive pulmonary disease (COPD), this study systematically analyzed the burden of the disease due to ozone (O₃) exposure in adults aged ≥ 65 years.

Methods: Data from the Global Burden of Disease Study 2021 were used to analyse trends in the age-standardized mortality rate (ASMR) for O₃-related COPD in the elderly (≥ 65 years). Age-period-cohort (APC) model was used to analyse independent age, period and cohort effects. Spearman's correlation coefficient assessed the relationship between ASMR and socio-demographic index (SDI). Decomposition analysis decomposed the drivers of change. Cross-country inequality analysis assessed health inequalities between countries. Frontier analysis estimated optimal health outcomes.

Results: From 1990 to 2021, the number of O₃-related COPD deaths in the elderly increased from 0.187 to 0.420 million globally. Male ASMR was higher than female ASMR and tended to decrease, whereas female adults ≥ 90 years of age had increased ASMR. ASMR is decreasing in 93 countries and increasing in 78 countries. The global burden of disease was largely driven by population and ageing, but low and low-middle SDI regions were positively affected by ageing, population and epidemiological changes. Global health inequalities remained pronounced, particularly in lower-developed countries. Frontier analyses also showed that countries and regions with lower levels of development had greater potential to improve the burden.

Conclusion: Despite an overall reduction in the disease burden, O₃-related COPD mortality remains a major health threat to the elderly, particularly in less developed countries and regions.