Some epidemiologic studies suggest that asthma prevalence and severity are decreasing in high-income countries. However, it appears that there is a large heterogeneity among populations.
The U.S. National Center for Health Statistics’ report "Asthma Prevalence, Health Care Use, and Mortality: United States, 2005-2009" (January 12, 2011) presents recent figures for the US. In 2009, current asthma prevalence was 8.2% of the U.S. population (24.6 million people); within population subgroups it was higher among females, children, persons of non-Hispanic black and Puerto Rican race or ethnicity, persons with family income below the poverty level, and those residing in the Northeast and Midwest regions. In 2008, persons with asthma missed 10.5 million school days and 14.2 million work days due to their asthma. In 2007, there were 1.75 million asthma-related emergency department visits and 456,000 asthma hospitalizations.
It is therefore of great importance to consider asthma as a major public health problem, in particular in underserved populations.