Asthma -- United States, 1980-1987
Respiratory asthma* (1) is a common chronic disease that affects persons in all age groups. Since the early 1970s, the prevalence, morbidity, and mortality of asthma in the United States and other countries have been increasing (2-5). In 1988, related health-care expenditures for asthma in the United States exceeded $4 billion (CDC/Health Care Financing Administration, unpublished data). This report summarizes national trends in disease burden for asthma using data from the CDC's National Center for Health Statistics' multiple cause-of-death file**, National Ambulatory Medical Care Survey (NAMCS), National Hospital Discharge Survey, and National Health Interview Survey (NHIS) (6-10).
From 1980 to 1987, the death rate from asthma, as the underlying cause of death, increased 31% from 1.3 per 100,000 population (2891 deaths) to 1.7 per 100,000 (4360 deaths) (Figure 1). During this period, the rate for females increased 50% (from 1.2 to 1.8 per 100,000); the rate for males increased 23% (from 1.3 to 1.6 per 100,000). Death rates were generally higher for older age groups; the highest rates were in persons greater than or equal to 65 years of age (7.9 per 100,000 in 1987).
The annual asthma death rate was consistently higher for blacks than for whites; for blacks the rate increased 44% (from 2.5 to 3.6 per 100,000), compared with a 36% increase (from 1.1 to 1.5 per 100,000) for whites (Figure 1). The average annual black-white rate ratio was 2.6 for males and 2.2 for females.
Asthma is generally treated in outpatient settings. Of an estimated 640 million ambulatory-care visits in the 1985 NAMCS, 6.5 million (1%) visits were for asthma as a first-listed diagnosis. Whites had a higher rate (28.0 per 1000 population) of outpatient visits for asthma than blacks (24.3 per 1000 population); females had a higher rate (28.9 per 1000) than males (25.7 per 1000). Rates were highest for persons less than 20 and greater than or equal to 65 years of age (33.1 and 33.3 per 1000, respectively). Females had higher rates of clinic visits than males at all ages except for those aged less than 20 years.
From 1980 through 1987, the hospital discharge rate for asthma as the first-listed diagnosis increased 6%, from 174.6 to 184.8 per 100,000 population (Figure 2). The highest age-specific hospitalization rates were consistently among those aged greater than or equal to 65 years. However, the highest rate increase (24%) was among those aged less than 20 years (from 196.8 to 245.0 per 100,000). Females had higher hospital discharge rates than males each year; blacks were more than twice as likely as whites to be hospitalized.
Editorial Note: The Year 2000 Health Objectives for the Nation seek to reduce morbidity from asthma (11)--yet, the data in this report show increases in morbidity and mortality from asthma and underscore substantial age-, race-, and gender-specific differences. Factors that may contribute to these increases include exposure to infections and other "triggers" for bronchoconstriction and inflammation, patterns of health-care use, patient compliance and understanding of treatment, current medical regimen (5), air quality (12), and the severity and prevalence of disease. The exacerbation of asthma is hypothesized to be primarily an inflammatory process of the bronchial airways (13). To better characterize the epidemiology of asthma in North America and Europe, the National Task Force on Asthma Morbidity and Mortality is collaborating with the European community in a survey of asthma prevalence. In addition, other studies are focusing on the natural history of asthma and the importance of respiratory viral infections (14), allergens, and other environmental or occupational exposures in the initiation and exacerbation of asthma.
In March 1989, the National Heart, Lung, and Blood Institute, National Institutes of Health, implemented the National Asthma Education Program (NAEP) to establish management guidelines for clinicians and to develop a comprehensive asthma education campaign for health professionals and patients in the United States. Goals of the program are to: 1) raise awareness that asthma is a serious chronic disease, 2) help ensure that patients recognize symptoms of asthma and that health professionals diagnose asthma, and 3) ensure effective control of asthma by encouraging partnership among patients, physicians, and other health professionals by using updated treatment regimens and education programs.
The NAEP determines its program direction and strategies through a coordinating committee comprised of national medical and health professional associations, voluntary health organizations, and federal agencies. The NAEP has also convened an expert panel to outline management protocols for acute and chronic asthma in children and adults. Since patient education is an integral part of asthma management (15-17), the report will emphasize the importance of patient education. The NAEP has also organized subcommittees to address school asthma education, professional education, and patient and public education while focusing on high-risk and minority populations for comprehensive programs and activities.
The findings in this report suggest that, to reduce morbidity and preventable mortality associated with asthma, health-care personnel and public health officials must promote timely and aggressive medical treatment (13) and physician-patient co-management (18). In addition, there is a need for consensus on an epidemiologic working definition for asthma (19) (e.g., diagnostic criteria and a case definition). Public health officials should also address issues of smoking, air quality, access to regular health care, and education in schools as these impact on asthma.
9. NCHS. National Health Interview Survey (machine-readable public-use data tape). Hyattsville, Maryland: US Department of Health and Human Services, Public Health Service, CDC, 1980-1987. 10. Irwin R. 1980-1988 Intercensal population estimates by race, sex, and age (machine-readable data file). Alexandria, Virginia: Demo-Detail, 1988. 11. Public Health Service. Healthy people 2000: national health promotion and disease prevention objectives (Draft). Washington, DC: US Department of Health and Human Services, Public Health Service, 1990. 12. Pope CA III. Respiratory disease associated with community air pollution and a steel mill, Utah Valley. Am J Public Health 1989;79:623-8. 13. Reed CE, Hunt LW. The emergency visit and management of asthma (Editorial). Ann Intern Med 1990;112:801-2. 14. Busse WW. The role of respiratory infections in asthma: update on asthma. Presented at the 1990 World Conference on Lung Health. Boston, Massachusetts, May 20-24, 1990. 15. Barnes PJ. A new approach to the treatment of asthma. N Engl J Med 1989;321:1517-27. 16. Wilson-Pessano SR, Mellins RB. Workshop on Asthma Self-Management: summary of workshop discussion. J Allergy Clin Immunol 1987;80(3(pt II)):487-90. 17. Clark NM. Asthma self-management education: research and implication for clinical practice. Chest 1989;95:1110-3. 18. Mayo PH, Richman J, Harris HW. Results of a program to reduce admissions for adult asthma. Ann Intern Med 1990;112:864-71. 19. Samet JM. Epidemiologic approaches for the identification of asthma. Chest 1987;91(suppl):74S-78S.
Modification, rubric 493.
** A public-use tape file that contains a data record for all deaths processed by NCHS. Each data record includes multiple cause, underlying cause, and demographic data for a death (6).