Verberne 1998.

Methods	Double‐blind, randomised, parallel‐group trial; multi‐centre
Participants	SYMPTOMATIC PARTICIPANTS RANDOMLY ASSIGNED: N = 87 ANALYSED: N = 87 INTERVENTION: ICS (beclomethasone 400 μg/d): 57 CONTROL: ICS (beclomethasone 800 μg/d): 30 WITHDRAWALS: reported AGE: mean (range) years INTERVENTION: ICS (beclomethasone 400 μg/d): 11.1 (6‐16) CONTROL: ICS (beclomethasone 800 μg/d): 11.4 (6‐16) GENDER: male N (%) INTERVENTION: ICS (beclomethasone 400 μg/d): 36 (63) CONTROL: ICS (beclomethasone 800 μg/d): 36 (60) ASTHMA SEVERITY: mild to moderate asthma ASTHMA DURATION: mean (range) years INTERVENTION: ICS (beclomethasone 400 μg/d): 8.5 years CONTROL: ICS (beclomethasone 800 μg/d): 9.0 years MEAN (± SD) β2‐AGONIST USE (puffs/d): not reported DOSE OF ICS AT STUDY ENTRY AND AT RUN‐IN: 200‐800 μg/d at least 3 months before the start of the study ATOPY (% of participants): 89% ELIGIBILITY CRITERIA FEV1 between 55% and 90% of predicted value Increase of at least 10% in FEV1 after inhalation of 0.8 mg salbutamol Airway hyperresponsiveness to methacholine greater than 2 standard deviations Ability to produce reproducible lung function tests History of stable asthma for at least 1 month without exacerbations or respiratory tract infections Use of ICS between 200 and 800 μg for at least 3 months before the start of the study EXCLUSION CRITERIA: not reported WITHDRAWAL CRITERIA: Participant needed 3 or more prednisolone courses within 3 months It was not ethical to continue blinded treatment according to the investigator Participant or parents wanted to stop
Interventions	PROTOCOL DURATION Run‐in = 6 weeks Intervention = 54 weeks DEVICE: All drugs were administered as Rotadisks in combination with a Diskhaler (Glaxo Wellcome, Greenford, UK) DOSE OF ICS INTERVENTION: beclomethasone 400 μg/d CONTROL: beclomethasone 800 μg/d CRITERIA FOR WITHDRAWAL FROM STUDY: reported
Outcomes	ANALYSIS: analyses of co‐variance OUTCOMES GROWTH MEASUREMENT TECHNIQUE: Height was measured using a stadiometer in centimetres, corrected to 1 decimal place PULMONARY FUNCTION TESTS FEV1 and PEFR (change from baseline during treatment) Airway responsiveness (change from baseline during treatment) FUNCTIONAL STATUS Daytime and nighttime symptoms Periods of exacerbations BIOMARKERS: not done ADVERSE EVENTS: reported WITHDRAWALS: reported
Notes	PUBLICATION: full paper (1998) FUNDING: Glaxo Wellcome BV CONFIRMATION OF METHODOLOGY: not received
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Using a computer random number generator: "Randomization was stratified by sex, age, center, baseline FEV1 and prior dose of ICS, using a computerized minimization method"
Allocation concealment (selection bias)	Low risk	Central allocation (including telephone, web‐based and pharmacy‐controlled randomisation): "independent randomisation center"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinding of participants and key study personnel ensured
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of participants and key study personnel ensured
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	Low risk	Study protocol not available but published reports include all expected outcomes, including those that were prespecified
Other bias	Low risk	Study apparently free of other sources of bias