Asthma: A Concern for Minority Populations
Allergic diseases, including asthma, are among the major causes of illness and disability in the United States. Illness and death from asthma have been increasing in this country for the past 15 years and are particularly high among poor, inner-city African-Americans. Although asthma is only slightly more prevalent among minority children than among whites, it accounts for three times the number of deaths. Low socioeconomic status, exposure to urban environmental contaminants, lack of access to medical care, and lack of self-management skills all contribute to the increase in deaths in minority communities.
The National Institute of Allergy and Infectious Diseases (NIAID), a component of the National Institutes of Health (NIH), supports basic, preclinical, and clinical research to prevent, diagnose, and treat infections and immune-mediated illnesses, including asthma and allergies.
Through basic and clinical research, as well as intervention programs, NIAID seeks to improve the diagnosis, treatment, and management of asthma, particularly in the minority populations disproportionately affected by this disease.
Growing Health Problem
Asthma is a growing health problem in the United States, particularly in inner-city African-American and Latino populations. Asthma is a chronic lung disease characterized by episodes of airflow obstruction. Symptoms of an asthma attack include
- Shortness of breath
- Chest tightness
Asthma occurs in people who are predisposed to develop asthma because of genetic and environmental factors that determine susceptibility. A variety of “triggers” may start or worsen an asthma attack, including
- Exposure to allergens
- Viral respiratory infections
- Airway irritants, such as tobacco smoke and certain environmental pollutants
Exposure of susceptible children to some of these triggers in early childhood, notably allergens such as house dust mites or cockroaches, may cause asthma.
Once asthma sufferers learn what conditions prompt their attacks, they can attempt to control their environments and avoid these triggers. Medical treatment with anti-inflammatory agents (especially inhaled steroids) and bronchodilators, however, is usually necessary to prevent and control attacks. With optimal management, people usually can control their asthma. Unfortunately, those living in inner cities cannot always get optimal care. Even currently available treatments do not control severe asthma in some patients, such as children in inner cities.
Asthma: A Health Disparity
NIAID’s Strategic Plan for Addressing Health Disparities identifies asthma as a key research area. The plan seeks to resolve health disparities by
- Directing funding for research on diseases known to occur disparately in a population.
- Identifying environmental, occupational, social, genetic, or biochemical factors that increase susceptibility to infectious and immunologic diseases.
- Increasing the participation and support of minority scientists interested in research on health disparities, including the number of minority scientists in training.
- Communicating research developments to the population groups affected by health disparities.
The Impact of Asthma
After a decade of steady decline in the 1970s, the prevalence of asthma, hospitalizations for asthma, and death due to asthma each increased during the 1980s and 1990s. Asthma affects an estimated 17 million Americans or 6.4 percent of the U.S. population. Children account for 4.8 million of the nation’s asthma sufferers.
Asthma affects slightly more African Americans (5.8 percent) than Americans of European descent (5.1 percent). In 1993, however, blacks were 3 to 4 times more likely than whites to be hospitalized for asthma. In 1994, there were 451,000 asthma-related hospitalizations in the United States. Children accounted for 169,000 of these. In 1995, asthma caused more than 1.8 million emergency room visits.
Asthma claims approximately 5,000 lives annually in the United States. Asthma deaths have increased significantly during the past two decades. From 1975 to 1979, the death rate was 8.2 per 100,000 people. That rate jumped from 1993-1995 to 17.9 per 100,000. Particularly alarming, the death rate from asthma for children ages 5 to 14 doubled from 1980 to 1993. African Americans were 4 to 6 times more likely than whites to die from asthma. The increasing prevalence of asthma in inner-city children underscores the need for new therapies to prevent asthma and reduce its prevalence.
Poverty, substandard housing that increases exposure to certain indoor allergens, lack of education, inadequate access to health care, and the failure to take appropriate prescribed medicines may all increase the risk of having a severe asthma attack or, more tragically, of dying from asthma.
Uncontrolled asthma also can impose serious limitations on daily life. Asthma is the leading cause of school absenteeism due to chronic illness and the second most important respiratory condition to cause home confinement for adults. Each year, asthma causes more than 18 million days of restricted activity, and millions of visits to physicians’ offices and emergency rooms. One study found that children with asthma lose an extra 10 million school days each year. This problem is compounded by an estimated $1 billion in lost productivity for their working parents. Asthma-related health care cost our nation approximately $10.7 billion in 1994, including a direct health care cost of $6.1 billion. Indirect costs, such as lost work days, added up to $4.6 billion.
National Cooperative Inner-City Asthma Studies
To address the special concerns about asthma in the inner city, NIAID launched the first National Cooperative Inner-City Asthma Study in 1991. The primary aim of the study was to find out why asthma disproportionately affects inner-city children and test new treatment and prevention methods. NIAID funds eight inner-city asthma study sites.
- Albert Einstein School of Medicine, New York, NY
- Case Western Reserve University, Cleveland, OH
- Children’s Memorial Hospital, Chicago, IL
- Henry Ford Hospital, Detroit, MI
- Howard University, Washington DC
- Johns Hopkins University, Baltimore, MD
- Mt. Sinai Medical Center, New York, NY
- Washington University, St. Louis, MO
Phase I of the first National Cooperative Inner-City Asthma Study (1991-1994) was designed to identify factors associated with severity of asthma in children ages 4-11. This investigation demonstrated that the combination of cockroach exposure and cockroach allergy was a major factor for asthma severity. The study developed and tested a one-year comprehensive educational, behavioral, and environmental intervention.
Phase I enrolled 1,528 children and their families. The study population was 73 percent African American, 20 percent Hispanic, and 7 percent Caucasian. Ninety-three percent of the participants completed the study.Asthma risk factors found to be present in these urban families included
- High levels of indoor allergens, especially cockroach allergen
- High levels of tobacco smoking among family members and caretakers
- High indoor levels of nitrogen dioxide, a respiratory irritant produced by inadequately vented stoves and heating appliances
This study provided the most convincing data that cockroach was the major allergen for inner-city children. Low soci