1. World Health Organization. World Health Organization (WHO) Website. Available from: https://www.who.int/zh/news-room/fact-sheets/detail/chronic-obstructive-pulmonary-disease-(copd). Accessed January 1, 2022.
2. World Health Organization. World health statistics 2021: a visual summary. Available from: https://www.who.int/data/stories/world-health-statistics-2021-a-visual-summary. Accessed February 1, 2022.
3. Chronic obstructive pulmonary disease: current burden and future projections
4. Global, Regional, and National Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life-Years for 29 Cancer Groups, 1990 to 2017
5. Global Initiative for Chronic Obstructive Lung. Global strategy for diagnosis, management, and prevention of COPD; 2022. Available from: https://goldcopd.org/. Accessed January 1, 2022.