Burden of chronic respiratory diseases and their attributable risk factors in 204 countries and territories, 1990-2021: Results from the global burden of disease study 2021.

Background: Chronic respiratory diseases (CRDs) remain a substantial global public health challenge, contributing significantly to morbidity and mortality worldwide. This study aimed to comprehensively characterize trends in CRD burden across various populations by examining differences by sex, age, and sociodemographic index (SDI). Methods: We performed a systematic analysis using data from the Global Burden of Disease (GBD) 2021 study, covering the period from 1990 to 2021 across 204 countries and territories. Estimates of age-standardized prevalence, mortality, disability-adjusted life years (DALYs), incidence, and annualized percentage changes for both 1990-2021 and 2019-2021 were calculated. Geographic and demographic variations were evaluated by age, sex, and SDI. The contributions of key risk factors-including tobacco use, ambient particulate matter (PM) pollution, household air pollution from solid fuels, and occupational exposure to PM, gases, and fumes-were also assessed. Results: In 2021, an estimated 468.3 million individuals globally were living with CRDs, with an age-standardized prevalence rate of 5785.4 per 100,000 population. CRDs accounted for 4.4 million deaths with age-standardized mortality rate of 53.6 per 100,000 population and 108.5 million DALYs with age-standardized DALY rate of 1294.6 per 100,000 population in the same year. Age-standardized prevalence rate decreased by 1.01 % from 1990 to 2021 but increased by 0.20 % from 2019 to 2021. From 2019 to 2021, the age-standardized incidence rate of CRDs increased slightly from 713.4 to 719.3 per 100,000 population, with an annualized percentage change of 0.41 %, while the age-standardized DALY rate continued to decline from 1321.9 to 1294.6 per 100,000 population, with an annualized percentage change of -1.04 %. Although the age-standardized mortality rate declined by 1.46 % over the full period, the absolute number of deaths rose as a result of demographic shifts, including population growth and aging. Globally, tobacco use remained the predominant risk factor, while household air pollution from solid fuels was the leading contributor to DALYs and mortality in low- and low-middle SDI countries. Conclusion: The global burden of CRDs remains both substantial and dynamic, underscoring the continued influence of risk factors such as tobacco use and household air pollution. These findings emphasize the urgent need for targeted public health interventions and more equitable healthcare resource allocation, particularly in low- and middle-SDI regions. Strengthened surveillance systems, improved access to care, and integrated strategies addressing both established and emerging risk factors are essential for reducing the global impact of CRDs.