According to national/international asthma guidelines, subjects with asthma can be classified into one of 4 categories (intermittent, or mild, moderate, or severe persistent) based upon lung function, symptoms, and albuterol use. Guideline criteria for mild asthma based on symptomatology or rescue use is broad, suggesting that they may not define a distinct group of patients.
This analysis evaluated 276 subjects previously receiving short-acting beta2-agonists alone from 5 completed 12-week trials in which subjects received placebo. Subjects were initially stratified by baseline PEF ≥80% or <80% predicted and further stratified by symptoms and/or albuterol use on ≤2 days/wk, 3-6 days/wk or 7 days/wk.
For subjects with PEF ≥80% and symptoms/albuterol use 1-2 days/wk, the majority of weeks were spent in intermittent (76%) or mild (11%) categories, based on overall assessment of asthma severity. By contrast, for subjects with PEF ≥80% and symptoms/albuterol use 7 days/wk, approximately 51% of weeks were spent in the moderate category. When subjects with PEF ≥80% and symptoms/albuterol use 3-6 days/wk were considered, subjects who would be classified with mild persistent asthma using current guidelines, approximately 34% of weeks were spent in moderate or severe categories. Furthermore, subjects with PEF <80% and symptoms/albuterol use on 3-6 days/wk, spent only 36% of weeks in intermittent or mild categories and those with PEF <80% and daily symptoms/albuterol spent only 20% of weeks in intermittent or mild categories.
This analysis clearly demonstrates that asthma severity cannot be determined in many pediatric subjects by discrete, point-in-time assessments of lung function, albuterol use or symptoms. More importantly, these observations suggest that the current classification system for persistent asthma needs to be re-evaluated as many pediatric subjects who meet current guideline criteria for mild persistent asthma would appear to be more appropriately classified as having moderate or severe persistent asthma.
These data highlight the importance of ensuring that pediatric patients are carefully monitored and receive appropriate maintenance therapy for asthma control.
Paul Dorinsky, Shareholder I am a GSK shareholder; Employee I am a GSK employee.