Study characteristics of the included randomised controlled trials

First author [ref.]Age groupDuration yearsAsthma definitionAsthma severityICS interventionSample sizeMean age yearsFemale %Pre-BD FEV1
L% pred
Beasley [17]Adults1Physician-diagnosed asthma; treatment with SABA only last 3 monthsMildBudesonide 200 µg twice daily#22534.95790.3
No placebo (open-label)22335.85189.2
Becker [18]Children1Physician-diagnosed asthma; ≥6 months of symptoms, FEV1 >75% predMildBeclomethasone 200µg twice daily1197.632.81.3991.3
Placebo, twice daily1217.734.71.4292.0
Boulet [19]Adults1Physician-diagnosed asthma; BHR and FEV1 >70% predMildFluticasone 100–250µg daily#352754.23.5597.2
Placebo daily342669.73.3398.5
den Otter [20]Adults2Symptoms typical of asthma; BHR or BDR; FEV1 decline ≥80 mL·year−1No restrictionFluticasone 250 µg daily#23
Placebo daily22
Jonasson [21]Children2.3Physician-diagnosed asthma; ≥1 exacerbation in last 12 months or ≥3 exacerbations everMildBudesonide 200 µg daily#3210.046.92.23102.1
Placebo daily349.435.32.04104.6
Juniper [22]Adults1Physician-diagnosed asthma; BHR and FEV1 >70% predNo restrictionBudesonide 200 µg twice daily#1642.462.589.9
Placebo twice daily1635.156.392.1
Merkus [23]Children2–3Physician-diagnosed asthma; BHR and FEV1 55–90% pred or FEV1/FVC 50–75% predModerate-severeBudesonide 100 µg three times daily3411.462.972.2
Placebo three times daily2010.976.773.5
O'Byrne [24]Mostly adults1Physician-diagnosed asthma; BHRMildBudesonide 200 µg twice daily#128239.062.284.2
Placebo, twice daily127740.060.484.1
Osterman [25]Adults1Physician-diagnosed asthma diagnosed within the last year; BHRNo restrictionBudesonide 200 µg twice daily#3833.057.93.3193.1
Placebo twice daily3735.054.13.2388.7
Pauwels [3]Adults and children3Physician-diagnosed asthma; recent onset ≤2 years; variable airflow limitationMildBudesonide 200–400 µg daily#359724.054.286.3
Placebo daily356824.054.086.6
Simons [26]Children1Physician-diagnosed asthma; BHR and BDR and FEV1>70% predMildBeclomethasone 200 µg twice daily819.641.01.8992.0
Placebo twice daily809.545.01.8896.0
Tonascia [27]Children4.3Physician-diagnosed asthma; BHRMild-moderateBudesonide 200 µg twice daily3119.041.893.6
Placebo, twice daily4189.044.094.2
Ward [12]Adults1Physician-diagnosed asthma; positive skin prick testing to ≥3 common aeroallergensMild-moderateFluticasone 750 µg twice daily+1796.0
Placebo twice daily1894.0

ICS: inhaled corticosteroid; BD: bronchodilator; FEV1: forced expiratory volume in 1 s; SABA: short-acting β2-agonist; BHR: bronchial hyperresponsiveness; BDR: bronchodilator reversibility; FVC: forced vital capacity. #: low-dose ICS; : medium-dose ICS; +: high-dose ICS.