According to the report, from 2001 to 2009 the prevalence of asthma increased among all demographic groups studied, including men, women, whites, blacks and Hispanics. Black children are most acutely affected: the study found that 17 percent of black children — nearly one in five — had a diagnosis of asthma in 2009, up from 11.4 percent, or about one in nine, in 2001.
While officials at the Centers for Disease Control emphasized that asthma could be controlled if managed effectively, they were at a loss to explain why it had become more widespread even as important triggers like cigarette smoking had become less common.
“We don’t know exactly why the number is going up, but, importantly, we know there are measures individuals with asthma can take to control symptoms,” said Ileana Arias, principal deputy director of the centers.
Agency officials declined to comment on budgetary proposals that would reduce money for the National Asthma Control Program.
Prevention depends on educating patients about appropriate use of medications and ensuring that each patient has a written medical plan to control asthma, but the report found that only one-third of patients had been given a plan and only about half had been advised to make changes to eliminate asthma triggers at home, school and work.
Paul Garbe, chief of the Air Pollution and Respiratory Health Branch at the centers, noted the success of several state public health initiatives, including one in Connecticut in which asthma educators and environmental assessors were sent into homes to advise patients on what changes needed to be made and how to manage the disease.
The report found that the overall prevalence of asthma increased to 8.2 percent in 2009, when 24.6 million cases were diagnosed, from 7.3 percent in 2001, when 20.1 million cases were diagnosed — a 12.3 percent increase. Among the most affected were children, 9.6 percent of whom had asthma, and especially poor children, of whom 13.5 percent had it.
While 7.7 percent of adults were found to have asthma, the rate was higher among women (9.7 percent) and among poor adults of both sexes (10.6 percent).
Asthma costs grew to about $56 billion in 2007, up from about $53 billion in 2002, the report said, though annual deaths attributed to asthma declined to about 3,500 in 2007, from a peak of about 5,500 deaths in 1996.
Researchers are investigating several potential causes for the increase in asthma, including exposure to various allergens, traffic exhaust fumes, pesticides and certain plastics, as well as factors like obesity and diet that may play a role, said Dr. Rachel L. Miller, director of the asthma project at the Mailman School of Public Health at Columbia University.
“There’s no easy singular explanation,” Dr. Miller said. “The more we study this, the more it raises a lot of questions. It’s not a straightforward puzzle at all.”
posted Apr 14th 2011 9:31PM 
Back in 2009, we told you about a University of Wisconsin-Madison scientist using GPS to tag asthmatics in an effort to better understand what was triggering their attacks. Two years later, David Van Sickle is about ready to turn his research into a commercial product dubbed the Spiroscout. The USB-powered inhaler uses GPS as well as WiFI to track patients' inhaler use, which Van Sickle says will yield a fuller, more accurate body of data than the self-recorded logs patients are often asked to keep. The benefit is two-fold, Van Sickle says: physicians can use this data to adjust their patients' medication, if necessary, while epidemiologists might have more insight into population-level trends. As PhysOrg notes, this isn't the first inhaler of its kind (that honor goes to SiliconSky GPS, though its product was also based on Van Sickle's first-iteration technology), but it may be the most practical one to date in that it doesn't come with a bulky box attached. Spiroscout isn't available just yet -- the company expects it to ship in the fall -- but curious asthmatics can reserve theirs now.