Prognostic factors predicting control of chronic asthma symptoms in children receiving prophylactic bronchodilator therapy.

The factors predicting the control of asthma symptoms were studied in 312 consecutive children with chronic asthma who were receiving chronic prophylactic bronchodilator therapy. Asthma symptoms were controlled in 232 (74.4%) patients but not in 80 (25.6%) patients after 18 months of therapy. The cumulative percentage of patients in whom asthma symptoms were controlled increased with the duration of therapy. During the first 6 months of therapy, children who had a history of exacerbation of symptoms by fear stimulus or by dust had respectively an 83.3% (p = 0.0001) and a 35.4% (p = 0.003) lower rate of control of asthma symptoms than children without such a history. Similarly, children with a history of worsening asthma symptoms following ingestion of cold foods or drinks had a 71.4% (p = 0.002) lower rate of control of asthma symptoms after 6-12 months of therapy than children without such a history. Certain factors are important for predicting control of asthma symptoms at different times following the initiation of therapy and may relate to the lability of the airways to these stimuli.