Global, regional, and national burden of lower respiratory infections and chronic obstructive pulmonary disease, 1990–2021: a systematic analysis from the global burden of disease study 2021

PURPOSE: This study evaluates the global burden of lower respiratory infections (LRIs) and chronic obstructive pulmonary disease (COPD), focusing on their combined impact across age groups and regions. METHODS: Data from 204 countries were analyzed using spatiotemporal Gaussian process regression to estimate LRI and COPD incidence, prevalence, and disability-adjusted life years (DALYs). Age-standardized ratios (ASR) and the Socio-Demographic Index (SDI) were used to compare disease burdens, with trends assessed via linear regression and restricted cubic spline models. RESULTS: In 2021, COPD and LRI caused 360 million cases and 5.9 million deaths, with the highest burden in low-SDI regions. COPD remained the fourth leading cause of death, while LRI dropped to seventh. CONCLUSION: The bidirectional link between LRI and COPD exacerbates disease progression, disproportionately affecting low-income regions and aging populations. Addressing disparities in healthcare access, improving vaccines, and strengthening public health infrastructure are critical to reducing the global burden of these diseases.