Asthma Prevalence Up 12% in Last Decade: CDC

Alison McCook

May 03, 2011

May 3, 2011 — Asthma now affects 1 in 12 Americans — an increase of 12% during the last decade — but only one third are using long-term control therapies such as inhaled corticosteroids, according to the US Centers for Disease Control and Prevention (CDC).

The findings reinforce clinicians' vital role in preventing asthma's potentially deadly consequences, said Ileana Arias, PhD, principal deputy director of the CDC, including prescribing long-term control medicine and teaching patients how to monitor and manage their condition. "Asthma attacks are not inevitable," Dr. Arias told reporters during a press conference today. "Asthma can be controlled."

The analyses were published today in "Vital Signs," a monthly edition of the CDC's Morbidity and Mortality Weekly Report, in honor of World Asthma Day.

The findings are based on data collected during the National Health Interview Survey, in which people provide health information during household interviews, and the Behavioral Risk Factor Surveillance System, an ongoing state-based telephone health survey of US adults.

The authors found that the overall prevalence of asthma in adults and children increased from 7.3% in 2001 to 8.2% in 2009, or from 20.3 million to 24.6 million people.

The rate of asthma increased among all subgroups, but asthma is currently more common in children (9.6%) than adults (7.7%). The most significant increase in prevalence occurred in black children, who saw an almost 50% rise in diagnoses from 2001 to 2009. Now, nearly 1 in 6 black children has asthma.

The rate of asthma appeared highest in low-income people, affecting 10.6% and 13.5% of poor adults and children, respectively.

Most people with asthma (89%) had health insurance, but among those who did not, more than 40% said they could not afford their prescription medications — a problem that affected only 11.5% of those who had health insurance. People without health insurance were also less likely to say they had consulted a primary care physician or specialist.

Only 34.2% of people with asthma said they had received a written asthma action plan, and only 68.1% said they had been taught how to respond appropriately when they experience symptoms of an asthma attack. Finally, only one third of adults and children said they were using long-term control medicine such as inhaled corticosteroids.

Action Plan Needed for All Patients With Asthma

In a conference call with reporters, Paul Garbe, DVM, MPH, chief of the CDC's Air Pollution and Respiratory Health Branch, reinforced the importance of a written asthma action plan, in which physicians and patients work together to develop a detailed, personalized description of how to control asthma and handle symptoms when they arise.

The CDC recommends that all patients with asthma receive a written action plan; it is not clear why most have not done so, Dr. Garbe told Medscape Medical News in response to a question asked during the press conference. A good plan takes time, he said, and it is possible that physicians believe that developing one "would possibly prevent them from providing care to other patients that day."

It is also not clear why more patients are being diagnosed with asthma — and therefore need a written action plan — than in previous decades, he added, particularly as outdoor air quality has improved and exposure to smoking has decreased in recent years. "We don't know exactly why the rate is going up," said Dr. Arias.

As the rate of asthma increases, so do its costs: In 2007, expenses related to asthma totaled approximately $56 billion, an increase of 6% since 2002, equaling roughly $3300 per person with asthma.

In 2008, approximately one half of people with asthma said they had experienced an asthma attack in the last 12 months, more than 40% of whom said their asthma had caused them to miss at least 1 day of school or work. Although the number of deaths from asthma has declined, almost 3500 people still die every year from the condition, said Dr. Garbe.

"Asthma is a serious, lifelong disease that unfortunately kills thousands of people each year and adds billions to our nation's healthcare costs," CDC Director Thomas R. Frieden, MD, MPH, said in a statement. "We have to do a better job educating people about managing their symptoms and how to correctly use medicines to control asthma so they can live longer more productive lives while saving healthcare costs."

Morb Mortal Wkly Rep. Published online May 3, 2011.


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