Respiratory diseases are among the leading causes of death worldwide (table 1). Lung infections (mostly pneumonia and tuberculosis), lung cancer and chronic obstructive pulmonary disease (COPD) together accounted for 9.5 million deaths worldwide during 2008, one-sixth of the global total. The World Health Organization estimates that the same four diseases accounted for one-tenth of the disability-adjusted life-years (DALYs) lost worldwide in 2008 (table 2).
The Global Burden of Disease (GBD) Study recently compared the contribution of major diseases to deaths and disability worldwide for 1990 and 2010. Among the leading causes of death, lower respiratory infections were ranked 3rd in 1990 and 4th in 2010, whereas COPD was ranked 4th in 1990 and 3rd in 2010. Lung cancer rose from 8th- to 5th- commonest cause of death, while tuberculosis fell from 6th to 10th position in the ranking.
The GBD Study also presented rankings for years lived with disability, among which asthma ranked 13th worldwide in 1990 and 14th in 2010, while COPD ranked 6th in 1990 and 5th in 2010. When premature deaths and disability were combined as DALYs lost, lower respiratory infections were ranked the leading cause worldwide in 1990, and the 2nd most important cause of DALYs lost in 2010. Also among the 25 most important causes were COPD (ranked 6th in 1990 and 9th in 2010), tuberculosis (ranked 8th in 1990 and 13th in 2010) and lung cancer (ranked 24th in 1990 and 22nd in 2010).