Fitzgerald 1996.

Methods	Randomised double‐blind trial
Participants	Study period: not reported Setting: emergency departments of 3 paediatric tertiary referral hospitals, Sydney, Australia Inclusion criteria: children aged 6 months to 6 years admitted to the emergency department based on a decision by the medical staff regarding croup severity. To be included in study children were required to have acute (viral) or spasmodic croup and a minimum Westley croup score of 6. Exclusion criteria: significant past or present systemic disease; pre‐existing known airway abnormalities; confirmed hypersensitivity to budesonide or L‐adrenaline; suspected epiglottitis; foreign body aspiration; bronchiolitis or asthma; need for immediate intubation or transfer to intensive care; treated with glucocorticoids in the 4 weeks prior to the study Baseline demographics (N = 67): proportion males: not reported mean (SD) age in months: treatment 1: 20.9 (12.7); treatment 2: 24.9 (12.5) mean (SD) modified Westley croup score: treatment 1: 7.1 (1.2); treatment 2: 7.7 (1.1)
Interventions	Treatment 1 (N = 35): single 2 mg/4 mL dose of nebulised budesonide Treatment 2 (N = 31): single 4 mg/4 mL dose of nebulised L‐epinephrine
Outcomes	Change in modified Westley croup score from baseline to 2, 12, and 24 hours; readmission to the hospital; intubation, use of epinephrine, and use of additional steroids
Notes	Funding source: Astra Pharmaceuticals
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: insufficient information provided to judge.
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information provided to judge.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: described as double‐blind, but nursing staff (personnel) were unblinded. Subjective outcomes
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The study medication was administered by nursing staff and the investigator was not present when the medication was placed in the opaque nebulizer bowl"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: 5% (N = 3) loss to follow‐up. All‐patients‐treated analysis excluded N = 1 child (1.5%). 13 children who received medications appropriately did not remain for the entire 24 hours. Last value extended for those who recovered before the 24‐hour period, however no children returned or were readmitted; unclear how this may have affected the findings.
Selective reporting (reporting bias)	Unclear risk	Comment: no protocol identified. All prespecified outcomes from methods appear in results.
Other bias	Low risk	Comment: no other sources of bias identified.
Overall risk of bias All outcomes	High risk	Comment: at least 1 domain judged as high risk.