Asthma Health Article

Demographics

In the United States, about 15 million people had asthma in 2004; approximately five million were children. Asthma affects individuals of all ages, but often starts in childhood. More than 50% of asthma cases occur in children between two and 17 years of age. Asthma is the most prevalent childhood chronic disease, and is more common in children than adults. In children, more males have asthma than females. Male children have a 30% higher prevalence of asthma compared to females. In adults, the trend is reversed, with more females having asthma than males. Adult females have a 30% higher prevalence of asthma than adult males. Within ethnic groups, non-Hispanic blacks have more asthma attacks and are more likely to be hospitalized and die from asthma than non-Hispanic whites. Asthma is distinct from, but closely linked to, allergies. Most, but not all, people with asthma have allergies.

The Centers for Disease Control (CDC) conducted a National Health Interview Survey in 2002 regarding asthma. At the time of the survey, 30.8 million individuals in the United States had been diagnosed with asthma during their lifetime: 21.9 million were adults and 8.9 million were children. Among all racial and ethnic groups, Puerto Ricans had the highest rate of lifetime asthma. Puerto Ricans were approximately 80% more likely than non-Hispanic whites to have been diagnosed with asthma.

Asthma attack prevalence is a crude indicator of how many individuals have uncontrolled asthma and are at risk for hospitalization. In 2002, 12 million people had experienced an asthma attack within the past year. Asthma attack prevalence decreased with age, being most prevalent in children. Puerto Ricans had the highest asthma attack prevalence, a full 100% higher than non-Hispanic whites. The prevalence of an asthma attack was about 30% higher in non-Hispanic blacks than in non-Hispanic whites. In this survey, Non-Hispanic blacks were the most likely to die from asthma, with an asthma death rate more than 200% higher than non-Hispanic whites. Females had an asthma death rate approximately 40% higher than males. Differences in male and female hormones may cause this disparity.

Asthma has been described as the fastest-growing chronic disease and a worldwide epidemic. According to Global Initiative for Asthma (GINA), an asthma research and education program, asthma accounts for about one in every 250 deaths worldwide. Many of the deaths are believed to be preventable and are caused by poor medical care. GINA estimates there are over three million asthmatic individuals worldwide. In most countries, asthmatic cases are increasing 20–50% every decade. The United States is one of the top countries for prevalence of asthma, along with England, Australia, parts of South America, and Canada. In Australia, the incidence of asthma is very high in Caucasian children, but much lower in aboriginal children.

It is speculated that lifestyle factors, such as a lack of physical activity, increased obesity, and more time spent indoors, may contribute to higher rates of asthma in highly developed countries. It is also possible that environmental irritants, such as poor indoor and outdoor air quality, along with the presence of potent irritants such as cockroach allergens, may contribute to higher rates of childhood asthma in poorer communities. Other factors that may prompt the onset of asthma are viral respiratory infections, low birth weight, and smaller-than-average air passageways in asthmatic patients.

Another area of research concerns the connection between common childhood infections and asthma. Many studies have shown that children who are exposed to viruses that cause the common cold and other respiratory infections at a very young age are less likely to develop asthma than peers living in a more hygienic environment. Children living at home with older siblings and those who spend time in daycare centers may be less likely to develop asthma than children who do not interact with others of their own age group. A related factor could be the overuse of antibiotics. Frequent use of antibiotic medications to treat relatively minor infections may produce changes in a person's immune system that increase the chance of developing asthma later in life.