Epidemiology and prevalence of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) represents one of the main causes of morbidity and mortality worldwide. According to the World Health Organization, approximately 3 million people in the world die as a consequence of COPD every year. Tobacco use remains the main factor associated with development of disease in the industrialized world, but other risk factors are important and preventable causes of COPD, particularly in the developing world. The purpose of this review is to summarize the literature on the subject and to provide an update of the most recent advances in the field.