RATIONALE: Little is known about the use of biomarkers in guiding treatment decision making in routine asthma management. This study was performed to compare measurement of bronchial hyperresponsiveness (BHR) with routine clinical measures to guide therapy.
METHODS: After a 2-week run-in period, subjects (˘12 years) were randomized to a BHR treatment algorithm (n=312) (treatment based on clinical markers [lung function, asthma symptoms, and bronchodilator use] and BHR) or a clinical treatment algorithm (n=154) (treatment based on clinical markers alone). Treatments were adjusted as needed every 8 weeks for 40-weeks according to the subject's derived severity class, which was based on clinical markers of asthma control with or without BHR.
RESULTS: Baseline values in the BHR and clinical algorithm groups, respectively were: ICS use 38% and 46%; FEV1 2.77L (83.1% predicted) and 2.80L (80.6% predicted); methacholine PC20 0.49mg/mL and 0.37mg/mL; rescue albuterol use on 3.2 days/week and 3.8 days/week; and asthma symptoms on 3.7 days/week and 4.4 days per week. During the study, BHR alone resulted in a treatment change for 32% of patients in the BHR algorithm, while BHR alone would have resulted in a treatment change for 33% of patients in the clinical algorithm.
CONCLUSIONS: This study demonstrated that although BHR alone dictated treatment decisions in some patients, for the majority (≥67%), BHR did not add to routine clinical measures of asthma control in guiding asthma treatment. These data suggest that asthma treatment directed at maintaining a high level of asthma control is an effective strategy.
