Since 2001, the prevalence of asthma among children increased at a rate of 1.4 percent per year, rising to 7 million children by 2010, a report published late last year by the Centers for Disease Control and Prevention says. Overall, the rate of asthma increased 2.9 each year, from 20.3 million people in 2001 to 25.7 million in 2010.
Asthma, a common childhood illness, has been linked to higher rates of school absenteeism, and from there to lower grades and test scores, my colleague Sarah D. Sparks has written over at the Inside School Research blog. Sarah noted that asthma itself may not be the sole reason behind low student achievement. The illness, more common among children living in poverty and from minority groups, may be a symptom of those children's living conditions. These kids are also disproportionately more likely to attend schools with lower indoor air quality.
The CDC report affirmed the connection between poverty and asthma. Asthma was more common in people whose family income is below the federal poverty threshold than among persons with family income at or above the federal poverty threshold, and its prevalence was significantly lower for each successively higher income level group.
Among children, the National Surveillance of Asthma says boys had higher prevalence of asthma than girls—11.1 percent compared with 7.8 percent—but that is flipped among adults. About 5.7 percent of men, compared to 9.7 percent of women, have asthma.
Asthma attacks, at least, seem to be declining slightly among children. In 2001, about 62 percent of children with asthma had at least one attack in which their airways constricted, making it difficult for them to breathe, compared to about 58 percent of children in 2010, the CDC report says. Attacks can be triggered by breathing in allergy-causing substances, such as dust, mold, pollen, or tobacco smoke.
A previous CDC report showed that in 2010, an estimated 10.1 million children—13.6 percent of American kids—had been diagnosed with asthma in their lifetimes, and 7 million, or 9.4 percent, still had asthma.
In 2008, children ages 5 to 17 who had one or more asthma attacks in the previous year months missed 10.5 million days of school.