Predictors of severe asthma exacerbations, poor asthma control and beta-agonist overuse in adult asthma

Background Predictors of severe asthma exacerbations, poor asthma control or beta-agonist overuse may be of clinical utility in the management of adult asthma patients. Aim To determine the baseline characteristics that are predictors of subsequent adverse outcomes. Methods A 24-week, open-label, parallel-group, multicentre RCT of 303 asthma patients studied the efficacy & safety of single budesonide/formoterol inhaler as maintenance & reliever therapy (SMART) or a fixed-dose regimen with salbutamol as reliever (‘Standard’). Inhaled medication use was measured by electronic monitoring. Baseline characteristics that were predictors of future severe asthma exacerbations, poor control [Asthma Control Questionnaire (ACQ)-5 score ≥1.5 at 6 months] & ‘extreme’ beta-agonist overuse [>20 total budesonide/formoterol actuations/day in SMART and >32 salbutamol actuations/day in Standard], were assessed by multivariate analyses. Results Lower FEV 1 % predicted [Odds Ratio (OR) (95% CI) 1.19 (1.02-1.39) per 10%], Standard therapy [OR 2.07 (1.19-3.60)], & female gender [OR 2.21 (1.15-4.24] were associated with greater risk of severe exacerbations. Higher ACQ-5 score [OR 1.45 (1.18-1.77) per 0.5 points] & older age [OR 1.04 (1.01-1.06) per decade] were associated with greater risk of poor control. Higher self-reported reliever use [OR 1.61 (1.23-2.12) per categorical score in ACQ question 6] & female gender [OR 2.06 (1.06-4.01] were associated with greater risk of extreme overuse. Conclusion Future severe asthma exacerbations, poor asthma control & beta-agonist overuse are predicted by different baseline characteristics & management approaches.