Heterogeneity and time course of asthma exacerbations: data from AUSTRI

Background: This analysis from the 6-month AUSTRI study (GSK115359, n=11,679) explored the rate and heterogeneity of severe exacerbations with fluticasone propionate (FP) alone compared with FP plus salmeterol (FSC) in patients aged ≥12 years with persistent asthma and a 1-year history of exacerbations. Methods: Primary cause of severe exacerbation was grouped as: environmental, allergic, infective and other. Patient characteristics according to exacerbation (yes/no), primary cause, and period before and after events (Day -14 to +14) vs a corresponding 29-day period in non-exacerbating patients, were analysed post-hoc. Results: 1077 (9.2%) patients reported ≥1 severe exacerbation during study. Exacerbation cause was recorded as environmental for 14.3% of exacerbations, allergic for 8.4%, and infective for 45.3%. Rate of asthma exacerbations was significantly reduced by 21.8% (Ratio: 0.782; 95% CI: 0.691-0.886) for FSC vs FP patients. In patients with exacerbation, mean rescue use (puffs/day) increased from 1.5 (Day -14) to 3.2 (Day 1) and back to 1.5 (Day +14), compared with mean 0.8 puffs/day in non-exacerbating patients (Fig. 1). Conclusions: In patients with a history of severe asthma exacerbations, regular twice-daily dosing with FSC was associated with a lower rate of asthma exacerbations compared with FP. Rescue medication use was higher pre- and post-exacerbation than the average for non-exacerbating patients. Funding: GSK (ID 213505)