Diagnosis and treatment of AERD: clinical practice realities

Abstract

RATIONALE: The Composite Asthma Severity Index (CASI) is a validated, multidimensional instrument for determining asthma severity using 5 domains: day symptoms and albuterol use, night symptoms and albuterol use, controller treatment, lung function, and exacerbations (Wildfire et al., JACI 2012). In this post hoc analysis from a randomized, controlled trial of omalizumab, CASI was examined as a tool for assessing impact of treatment intervention in children > _6 to <12 years with moderate-to-severe persistent allergic asthma. METHODS: Poisson regression analysis examined exacerbation rate reductions for omalizumab versus placebo at Week 24 stratified by median CASI score at baseline (< _7 (n5360) vs. >7 (n5216)). A higher CASI score indicates more severe asthma. Clinically significant exacerbations were defined as those requiring either systemic corticosteroid therapy or a doubling of baseline inhaled corticosteroid dose for > _3 days. RESULTS: Baseline age, sex, total IgE and eosinophil levels were similar between treatment groups and across CASI strata. The CASI>7 group had higher proportions of black children, males, lower mean percent predicted pre-bronchodilator FEV 1 , and greater maximum reversibility than the CASI< _7 group. Exacerbation rates were reduced by the following for omalizumab versus placebo: CASI< _7, 20% (-16%, 44%; p50.24); CASI>7, 45% (18%, 63%; p50.004). CONCLUSIONS: CASI is a useful clinical tool to identify children who are likely to achieve favorable response to omalizumab. In children with greater asthma severity, as measured by a higher CASI score, a significantly greater response to omalizumab was observed for exacerbation reduction versus placebo; children with lower CASI scores had nonsignificant differences in reductions in exacerbation rates.