Table 3– Definition of severe asthma for patients aged ≥6 years
Asthma which requires treatment with guidelines suggested medications for GINA steps 4–5 asthma (high dose ICS# and LABA or leukotriene modifier/theophylline) for the previous year or systemic CS for ≥50% of the previous year to prevent it from becoming “uncontrolled” or which remains “uncontrolled“ despite this therapy
 Uncontrolled asthma defined as at least one of the following:
  1) Poor symptom control: ACQ consistently ≥1.5, ACT <20 (or “not well controlled” by NAEPP/GINA guidelines)
  2) Frequent severe exacerbations: two or more bursts of systemic CS (≥3 days each) in the previous year
  3) Serious exacerbations: at least one hospitalisation, ICU stay or mechanical ventilation in the previous year
  4) Airflow limitation: after appropriate bronchodilator withhold FEV1 <80% predicted (in the face of reduced FEV1/FVC defined as less than  the lower limit of normal)
 Controlled asthma that worsens on tapering of these high doses of ICS or systemic CS (or additional biologics)
  • #: the definition of high dose inhaled corticosteroids (ICS) is age-specific (table 4). GINA: Global Initiative for Asthma; LABA: long-acting β2-agonists; CS: corticosteroids; ACQ: Asthma Control Questionnaire; ACT: Asthma Control Test; NAEPP National Asthma Education and Prevention Program.