Sung 1998.

Methods	Design: randomised controlled trial Method of randomisation: block randomisation in groups of 4 to 6 stratified by age (6 months to < 5 years, and > 5 years) and by concurrent use of ICS Means of allocation concealment: randomisation sequence concealed to all study personnel, identical drug packages Blinding: double‐blind, identical packages of study drugs made indistinguishable from each other and identified only by a study number Withdrawal/drop‐outs: all subjects accounted for
Participants	Eligible: 82 referred. 38 excluded for: PIS < 5 (32), declined (2), congenital heart disease (1), chicken pox exposure (1), assessed too late (1), ICS use (1) Randomised: 44 (24/20) Completed: 44 Age (mean) (years): study group 4.4, control group 3.5. Range: 6 months to 18 years Sex (M/F): 80%/20% Asthma diagnosis: wheezing on at least 2 prior occasions Inclusion criteria: PIS ≥ 5 and ≤ 11 Major exclusion criteria: acute exacerbation ≤ 2 weeks prior, use of systemic glucocorticoids < 1 month prior, previous enrolment, presence of any underlying disease that could affect the patient's cardiopulmonary status Baseline PIS median (range): budesonide 7 (6 to 8.8), placebo 7 (6 to 8)
Interventions	Setting: tertiary care paediatric hospital in Canada Study group received nebulised budesonide 2 mg x 1 dose Control group received normal saline placebo Both groups were given oral prednisone 1 mg/kg (maximum 50 mg) x 1 dose and salbutamol 0.15 mg/kg x 3 doses then every hour x 4 h. Supplemental oxygen was given as needed to maintain O2 saturation > 92%
Outcomes	Primary outcome was PIS, which was correlated with FEV1/FVC in asthmatic children > 6 years. Secondary outcomes included oxygen saturation, HR and co‐interventions including the use of extra doses of salbutamol, ipratropium bromide use and IV glucocorticoid use. Other outcomes included admission, length of hospitalisation and relapse of wheezing
Notes	The author was contacted and provided additional data from the study. ICS versus placebo, both groups received systemic corticosteroid
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Details of how the random sequence was generated are not available in the trial report. Block randomisation in groups of 4 to 6 stratified by age (6 months to < 5 years, and > 5 years) and by concurrent use of ICS
Allocation concealment (selection bias)	Low risk	Randomisation sequence concealed to all study personnel, identical drug packages
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Trial reported as double blind
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of study personnel responsible for outcome assessment indicates the risk of detection bias would be low
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No indication of patients being withdrawn from trial
Selective reporting (reporting bias)	Unclear risk	No apparent indication of reporting bias