A study of preschool-age, inner-city children with asthma found marked fluctuations in the degree of asthma control within 3 months, suggesting that frequent evaluations of asthma control in this population may be warranted, investigators reported.
“We know asthma is an unstable disease, but we underestimated just how unpredictably it could behave over time, especially in inner-city kids,” the study's lead author, Dr. Hemant P. Sharma, noted in a statement issued by Johns Hopkins University, Baltimore, where he is a pediatric allergist.
The 6-month study of 150 predominantly black children aged 2–6 years (mean age 4.4 years) with asthma living in Baltimore evaluated their long-term controller medication use and their use of asthma-related health care at baseline, and at 3 and 6 months. At baseline, the children were classified into National Asthma Education and Prevention Program control categories for asthma: mild intermittent (37%), mild persistent (17%), moderate persistent (21%), and severe persistent (25%).
Only 39% of the children reported long-term use of controller medication (inhaled corticosteroids, cromolyn and nedocromil, oral leukotriene modifiers, long-acting β-agonists, and oral theophylline), wrote Dr. Sharma and his associates.
At 3 months, asthma control had deteriorated in 46% of the children who had mild intermittent asthma at baseline and in 33% of those with mild persistent asthma at baseline. Changes in control also were seen at 3 months in more than half of the children with moderate persistent asthma at baseline and in about half of those with severe persistent asthma at baseline.
Among children with persistent symptoms at baseline, “even greater shifts were observed between baseline and 6 months,” at which time a change in the degree of asthma control was seen in more than two-thirds of the children with persistent symptoms at baseline (Pediatrics 2007;120[5]:e1174–81).
These results “underscore the labile nature of asthma,” and suggest that assessments of asthma control in young, inner-city children “should be repeated at least every 3 months to take advantage of opportunities to prevent future morbidity,” Dr. Sharma and his associates said.
Poor control of asthma was an independent predictor of the children's use of asthma-related health care (unscheduled doctor visits, emergency department visits, and hospitalizations) during the preceding 3 months, with a significant association between poor asthma control and recent use of asthma-related health care, “suggesting that asthma control is related to overall recent disease activity,” they said. For example, 5% of those with mild intermittent asthma had an unscheduled doctor visit related to asthma within the previous 3 months, compared with 23% of those with moderate persistent asthma, and 42% of those with severe persistent asthma.
Their reported use of long-term controller medications, however, was not an independent predictor of their use of asthma-related health care.
The ability to accurately identify children who are at the greatest risk of morbidity in the future is a “key component” of successfully preventing asthma-related health care use and targeting high-risk children, but information about which clinical factors predict the risk of future asthma-related health care use among children is lacking, the authors wrote.
These findings have “direct implications to inner-city black children, who bear much of the asthma burden in the United States.” The authors indicated they have no financial relationships to disclose.