Fig. 1
From: The impact of allergic rhinitis on the management of asthma in a working population
Classification of asthma severity based on the clinical severity and the treatment. Step 1: no medication or only “inhaled short-acting β2 agonists”; Step 2: inhaled corticosteroids daily or leukotriene modifier; Step 3: all subjects not allocated to the other groups; Step 4 (severe-persistent): oral corticosteroids daily or ≥3 short treatments in the previous 12 months or inhaled treatment combination of inhaled corticosteroids and inhaled long-acting β2 agonists