To evaluate the long term effects of anti-inflammatory therapy compared to bronchodilator therapy on the course of asthma, particularly on lung function and bronchial hyperresponsiveness, and on physical and psychosocial growth and development.

BACKGROUND:

Asthma is a serious chronic condition, affecting approximately 14 million Americans. People with asthma experience well over 100 million days of restricted activity annually, and costs for asthma care exceed $10 billion a year. Asthma is much more prevalent among children than adults.

Hospitalizations for asthma have been increasing among children. For example, from 1979 to 1987, the hospital discharge rate with asthma as the first-listed diagnosis rose 43 percent among children less than 15 years of age, from 19.8 to 28.4 discharges per 10,000 population.

Death rates for asthma are greater in Blacks than in whites, and the difference is increasing. In 1979, Blacks of both sexes were about twice as likely to die from asthma as whites. Over the past decade this ratio has increased, and by 1987 the asthma death rate was almost three times greater among Blacks than whites. In children, these mortality differences between Blacks and whites are even more striking.

Current knowledge about the epidemiology and natural history of childhood asthma is incomplete, but the relationship between asthma early in life and development of chronic obstructive pulmonary disease (COPD) in adulthood is becoming more apparent. Asthmatic children with persistent and severe asthma symptoms have lower levels of lung function by young adulthood than those with milder disease. Recent longitudinal studies have confirmed a decrease in rate of growth of lung function as measured by FEV1 among symptomatic (primarily wheeze) children compared to asymptomatic children. Among persons who develop COPD, initial level of lung function is the strongest predictor of subsequent rapid decline of ventilatory function.

Thus, less than maximally attained levels of lung function among children with asthma may predispose them to greater than normal decline of lung function later in life. Although the long-term effect of treatment on the course of asthma is not known, the treatment goal of decreasing bronchial hyperresponsiveness and maximizing lung function and growth during childhood may have a beneficial effect on lung health throughout life and prevent progression to irreversible airflow obstruction.

Two classes of medications are currently available for treatment of inflammation--corticosteroids and cromolyn sodium. Inhaled corticosteroids have significantly fewer side effects than systemic administration. Corticosteroids do not inhibit the early asthmatic response, but are effective in suppressing the inflammation and bronchial hyperresponsiveness of the late phase response. Long-term studies of inhaled corticosteroids have shown beneficial effects on lung function as measured by FEV1. However, there has been concern about possible effects of long-term use of inhaled corticosteroids. Although epidemiological studies of the use of inhaled corticosteroids have shown no significant adverse effects, large-scale randomized controlled studies of their effects on children's growth and development are needed.

When CAMP was initiated in the United States, bronchodilator treatment was the most common approach to therapy. Two classes of bronchodilators, inhaled beta-2-adrenergic agonists and oral theophylline, are most frequently prescribed for asthma. To date, no randomized, controlled studies have compared the two classes of anti-inflammatory medications to each other and to bronchodilator therapy on the course of asthma.

The initiative was proposed by the Pulmonary Disease Advisory Committee working group in October 1987 and approved by the full committee at the February 1988 meeting and by the National Heart, Lung, and Blood Advisory Council in May 1990. The Request for Proposals was released in October 1990. Awards were made in September 1991.

DESIGN NARRATIVE:

Children were randomized to one of three treatment groups to receive either: inhaled albuterol alone, albuterol with inhaled budesonide, albuterol with nedocromil. Upon randomization, data were collected on demographic factors, physical and psychosocial development, clinical factors including medical history and extent of allergies, and quality of life factors including limitation of activity, absenteeism from school, emergency room visits, and hospitalizations. All subjects received a common educational program, differing only in the information presented regarding the medication used by the subjects. Each subject was given a standard protocol for dealing with asthma attacks. All subjects were treated and followed for five years with quarterly visits yearly. Recruitment began in July 1993 and ended in June 1995 with the accrual of 1,041 subjects.

The study has been extended for an additional eight years to observe the subjects but not provide asthma treatment. This will allow CAMP to determine the full impact of 4 to 6 years of anti-inflammatory therapy on attaining maximal lung function and final height and on the natural history of asthma through age 26.

Asthmatic boys and girls, ages 5 to 12 at baseline.