The proportion of Americans with asthma increased from 7.3% in 2001 to 8.4% in 2010, marking the highest level ever, the U.S. Centers for Disease Control and Prevention said Tuesday. In 2010, an estimated 18.7 million adults and 7 million children had the disease -- one in every 12 Americans. Overall, about 29.1 million adults have been diagnosed with asthma at some point in their lives, but many of those were misdiagnosed or have apparently recovered, leading to the current figure of 18.7 million.
Asthma is a chronic airway disorder characterized by periods of irreversible airflow obstruction caused by inflammation of the airway and contraction of small muscles surrounding it. It can be triggered by exercise, infections, allergies, occupational exposures and airborne irritants such as tobacco smoke. Symptoms include wheezing, coughing, shortness of breath and chest tightness. Symptoms can usually be controlled with a variety of drugs, but there is no known cure and no known way to prevent development of the disorder.
Epidemiologist Christopher J. Portier of the CDC’s National Center for Environmental Health and his colleagues collected data using the agency’s Asthma Call-Back Survey, an in-depth survey conducted among people with asthma identified by the CDC’s Behavioral Risk Factor Surveillance System. The researchers released the data in a new report, “Asthma’s Impact on the Nation.”
In 2009, the most recent year for which data are available, asthma accounted for 3,388 deaths in the United States, 479,300 hospitalizations, 1.9 million ER visits and 8.9 million visits to physicians’ offices, the CDC said. The estimated costs to society were $50.1 billion per year due to medical expenses, $3.8 billion resulting from missing work and school, and $2.1 billion from premature deaths.
Children (9.5%) had a higher asthma prevalence than adults (7.7%), suggesting that the disease will become a bigger problem in the future. Females (9.2%) had a higher prevalence than males (7%). People of multiple race had an incidence of 14.1%, while Asians had the lowest (5.2%). Blacks were at 11.2%, while whites were at 7.7%. Hispanics of Puerto Rican descent had the highest prevalence, 16.1%. Death rates were highest for women, blacks and people over the age of 65.
“A key component [of care] for adults and children is to create and follow an asthma action plan,” Portier said. “Significantly, this analysis reveals that more than half of all children and more than two-thirds of adults with asthma do not have an individualized action plan. CDC encourages those with asthma to work with their doctors to take control of this disease.”