History of serious asthma exacerbations should be included in guidelines of asthma severity

Background It is unclear whether asthma severity measured with consensus guidelines is better than a history of a serious asthma exacerbation in predicting current disease activity and future clinical course. Objectives We sought to (1) compare asthma severity determined by using the Global Initiative for Asthma guidelines with a history of a serious asthma exacerbation as predictors of pulmonary function, bronchial hyperreactivity, and disease activity and (2) determine whether exacerbation history significantly adds to asthma severity in its ability to predict the same variables. Methods Forty-eight adolescents with a history of a serious asthma exacerbation were compared with 69 adolescents with asthma but without such a history. Groups were matched for age, sex, and ethnicity (age, 14.59 ± 1.74 years; 56% male; 58% white). Results Forty-two percent of subjects had severe, 28% had moderate, 15% had mild persistent, and 15% had mild intermittent asthma. Asthma severity and exacerbation history were associated with pulmonary function and markers of disease activity, whereas only exacerbation history predicted bronchial hyperreactivity ( P ≤ .001). Including exacerbation history significantly augmented the ability of the severity categories to predict the asthma measures. Conclusion Although asthma severity and a history of a serious asthma exacerbation both predict pulmonary function abnormalities and current disease activity, bronchial hyperreactivity was only associated with exacerbation history. Exacerbation history improves the ability of severity to predict these key asthma measures. Clinical implications Adding a history of a serious asthma exacerbation to the consensus guidelines for asthma severity is likely to improve the ability of these clinical tools to predict current disease activity and future clinical course.