How Big of a Problem Is Childhood Asthma?
Asthma is a chronic respiratory disease associated with intermittent episodes of coughing, wheezing, chest tightness, and respiratory distress. These episodes may be extremely alarming to children as well as their families. In addition to these more acute episodes, asthma may result in frequent symptoms which can lead to activity limitation, sleep disruption, and school absenteeism. These asthma symptoms are chronic and troublesome and may be present in children who have never required emergency care for their illness. Another common feature of childhood asthma is prolonged and/or recurrent respiratory infection with protracted symptoms of coughing and wheezing. The complaint of recurrent pneumonia or lower respiratory tract infections with wheezing is particularly common and should also alert the physician to the possibility of asthma.
Despite ongoing advances in our understanding of the pathophysiology and treatment of asthma, it remains a significant cause of morbidity and mortality in children. For reasons that remain unclear, the prevalence of asthma in children increased steadily over 15 years between 1980 and 1995. During this time, the prevalence of asthma nearly doubled (Figure 1-1). In 1997, the National Health Interview Survey was redesigned with expanded asthma definitions; however, review of the prevalence before and after this change showed that asthma remained at a similar high level. Current asthma prevalence has continued to climb steadily during the past decade as well. In 2005, pediatric asthma prevalence was estimated at nearly 6 million children (8.9%). In 2007, the prevalence had increased to 9.1%, and the most recent data from 2009 estimate an asthma prevalence of 9.6% (7.1 million children). In the National Health Interview Survey, there were an additional 3 million children who had a history of asthma previously (but not currently), bringing the total prevalence of children between the ages of 0 and 17 with a “history of asthma” to 12.7%. These sobering statistics make asthma the most common chronic lung disease of childhood, and it is clear that a significant asthma epidemic continues unabated in the United States.
Figure 1-1. Asthma prevalence among children 0 to 17 years of age for measures of asthma prevalence available in each year, United States, 1980–2005. (Adapted from data from the Centers for Disease Control/National Center for Health Statistics, National Health Interview Survey.)
The care of this significant number of asthmatic patients has an enormous impact on medical resource utilization. In the ambulatory setting, there has been a significant increase in physician office and outpatient hospital visits for asthma despite a plateau in the prevalence of asthma. This is likely multifactorial, including increased public awareness of asthma symptoms and severity, the need to establish severity and control, and increased focus on early interventions during acute exacerbations. In 2004, nearly 2.5% of all physician outpatient visits for children were due to asthma (6.5 million visits).
Asthma exacerbations are often managed in the emergency department. Despite the increase in the number of outpatient asthma visits to primary care physician offices, there has been no decrease in the number of emergency department visits. The frequency of emergency department visits has been fairly stable over the previous 15 years. In 2004, asthma exacerbations in children represented 2.8% of all emergency department visits (750,000 visits). While this figure decreased somewhat to 640,000 in 2007, this remains a significant concern because recurrent visits to the emergency department for asthma flares are a risk factor for dying from asthma. In fact, the prevention of emergency department visits is an important clinical and quality outcome goal, indicating that emergency care for asthma episodes should be a routine topic of conversation during regular asthma follow-up care.
Children with asthma exacerbations that are not responsive to outpatient therapy are admitted to the hospital. Hospital admission can be a stressful experience for children and their families and results in further disruption of their lives and activities. Hospitalization rates for asthma have followed prevalence rates for asthma with several years of incline followed by a plateau at recent high levels. Asthma exacerbations accounted for 3% of all hospitalizations of children (nearly 200,000 hospitalizations). At my own institution, asthma is among the most common discharge diagnosis. The average length of stay is approximately 2 days and a significant proportion (~20%) of children with asthma require repeated admissions for the management of their disease.
Rarely, children can die from their asthma. Mortality rates from asthma rose in parallel with the prevalence of asthma through much of the 1980s and 1990s; however, there was a decrease in asthma mortality from 1999 to 2004. In 2004, there continued to be 2.5 asthma deaths per 1 million children (186 deaths total). Of all the available asthma therapies, inhaled corticosteroids have been shown to be protective against asthma mortality in children.
Cumulatively, the 2010 direct cost of the care for asthma in the United States is estimated at $15.6 billion of health care expenditures. An additional $5.1 billion is related to indirect costs associated with morbidity and mortality, for a total of more than $20 billion! There are nonmonetary costs of asthma as well. The 4 million children with 1 asthma attack in the previous year missed a combined total of 12.8 million school days. Asthma causes a significant number of missed work days for the parents of these children in addition to the 10 million missed work days for adults with asthma.
Despite improved understanding of the pathophysiology of asthma and its treatment, the cost of childhood asthma in terms of money, disability, and lives lost remains high. This combination of medical, psychosocial, and economic factors is often referred to as the “burden” of asthma both to children and society, and reducing this burden remains a critical goal for those of us caring for this common and morbid condition.
Akinbami L. The state of childhood asthma, United States, 1980-2005. Advance data from Vital and Health Statistics, Centers for Disease Control and Prevention. 2006;381:1-28.
Akinbami LJ, Moorman JE, Garbe PL, Sondik EJ. Status of childhood asthma in the United States, 1980-2007. Pediatrics. 2009;123:S131-S145.
National Asthma Education and Prevention Program. Expert panel report 3 (EPR-3): guidelines for the diagnosis and management of asthma. Bethesda, MD: National Heart, Lung, and Blood Institute, 2007. NIH publication no. 08-4051.
National Institutes of Health. National Heart, Lung, and Blood Institute Chartbook on Cardiovascular, Lung, and Blood Diseases. Washington, DC: U.S. Department of Health & and Human Services; 2009.