摘要
Asthma is a chronic inflammatory disease that affects 300 million people worldwide. Its prevalence rangesfrom 1% to 18% of the population in different countries. The World Health Organization has estimated that 15 million disability-adjusted life years are lost annually due to asthma. Worldwide deaths from asthma are estimated at 250 000 per year. Furthermore, asthma is a major cause of absence from work in many countries, including United States .
Asthma is a chronic inflammatory disease that affects 300 million people worldwide. Its prevalence rangesfrom 1% to 18% of the population in different countries. The World Health Organization has estimated that 15 million disability-adjusted life years are lost annually due to asthma. Worldwide deaths from asthma are estimated at 250 000 per year. Furthermore, asthma is a major cause of absence from work in many countries, including United States .
