Demographic and clinical characteristics of children and adolescents with severe or difficult-to-treat asthma

Background: Young patients with severe or difficult-to-treat asthma are an understudied population. Objective: To assess age-associated and gender-associated differences in children and adolescents in the observational study, The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens. Methods: Cross-sectional baseline data for patients greater than or equal to 6 years and less than or equal to 17 years (n = 1261) were stratified by age group (6-8, 9-11, 12-14, and 15-17 years). The x(2) test for categorical variables and analysis of variance for continuous variables were used to identify differences among age groups, stratified by gender. Results: Most patients had moderate (55%) or severe (41%) asthma by physician assessment. Of those using greater than or equal to 3 long-term controllers (62%), 53% of children (6-11 years) and 44% of adolescents (12-17 years) reported an oral corticosteroid burst and 25% and 19%, respectively, had an emergency department visit in the previous 3 months; 10% and 15%, respectively, reported past intubation. In females, weight for age ranged between the 67th and 70th percentiles; height for age was between the 42nd and 54th percentiles (P < .01 among age groups). Lung function was lower in adolescents than children: prebronchodilator percent predicted forced expiratory volume in 1 second (FEV1)/forced vital capacity was 0.92 (6-8 years) and 0.83 (15-17 years), P less than .05, in males; and 0.94 (6-8 years) and 0.87 (15-17 years), P less than .05, in females. Conclusions: Children and adolescents demonstrated high rates of health care use and loss of lung function, despite using multiple long-term controllers. Clinical implications: Asthma treatments that prevent loss of lung function and reduce health care resource use are needed in young patients with severe or difficult-to-treat asthma.