About one in 12 people in the United States now has asthma, a total of 24.6 million people and an increase of 4.3 million since 2001, the Centers for Disease Control and Prevention said this week. • The cost of medical care for these patients increased by about 6 percent between 2002 and 2007, totaling $56 billion in the latter year, according to information in the CDC's Morbidity and Mortality Weekly Report. • The increases come despite improved air quality throughout most of the country and widespread decreases in smoking.
"We don't know exactly why the rate is going up," Ileana Arias, principal deputy director of the CDC, said in a news conference. "But measures can be taken to control asthma symptoms and exacerbations, and many asthma attacks can be prevented," she said.
Asthma is a chronic disease that is marked by wheezing, breathlessness, chest tightness and nighttime and early morning coughing. Common triggers include tobacco smoke, mold, air pollution and infections such as influenza and colds. Several studies have also shown a connection between obesity and asthma.
The disease is generally treated with two classes of medications: beta-agonists to provide quick relief when patients are having symptoms, and inhaled corticosteroids or a combination of steroids and long-acting beta-agonists to control persistent asthma.
Researchers have changed the way they measure the incidence of asthma in the population, so direct comparison to rates in the 1990s is not possible, said Paul Garbe, chief of the CDC's air pollution and respiratory health branch. But there has been a continuing increase in the incidence over the last several decades, he said. "The trends are going up," he noted.
One trend, however, has changed, he added. In the 1980s and 1990s, there was a dramatic increase in the number of people who died from asthma, but the numbers have been declining. In 2007, there were 3,447 deaths attributable to asthma, about nine every day. "That (decrease) is the one bright spot."
Asthma is more common in children, with about 9.6 percent reporting the disease, compared with 7.7 percent of adults. Boys are particularly affected, with 11.3 percent of them having the disease. The biggest increase in asthma rates was among black children, an almost 50 percent increase between 2001 and 2009. Seventeen percent of black children now have the disease.
Average annual asthma costs in the nation were $3,300 per person over the course of the decade, according to the report. About 90 percent of those with asthma said they had health insurance, but 11 percent of those said they still could not afford their asthma medications. About 40 percent of those without insurance said they could not afford their medications.
One of the key measures in treating asthma is for physicians to prepare a written asthma action plan to teach patients how to manage their symptoms, including how to avoid asthma triggers and how to take their medications properly. Many physicians do not prepare such written plans, Garbe said, perhaps because they feel they do not have sufficient time to do so.
Many states are now also developing plans for home environmental assessments and educational sessions to help patients manage their disease. Work in some states has shown that these efforts reduce visits to the emergency room significantly.
But severe budget deficits in states and the federal government may impair such efforts in the future, according to the American Lung Association. The president's proposed budget, the association said, would reduce funding for in-home visits and other asthma programs by as much as 50 percent and reduce the number of states funded by the National Asthma Control Program from 36 to 15. At least half of the CDC-funded school-based asthma programs would also be eliminated, the group said.