Geelhoed 1996.

Methods	Randomised double‐blind controlled trial
Participants	Study period: not reported Setting: emergency department of Princess Margaret Hospital for Children, Perth, Australia Inclusion criteria: children older than 3 months presenting to the emergency department with a diagnosis of croup (acute onset of inspiratory stridor, barking cough, hoarseness, and chest wall retractions) not severe enough to warrant admission Exclusion criteria: other acute or chronic medical problems; families that did not have a telephone or had limited English language abilities; received any type of steroids in the preceding week; pre‐existing upper airway condition; history of prolonged stridor; clinical picture that suggested a diagnosis other than croup Baseline demographics (N = 100): proportion male: treatment: 68%; control: 72% mean (SD) age in months: treatment: 37 (23); control: 45 (26) mean croup score: treatment: 0.9; control: 0.9
Interventions	Treatment (N = 50): single 0.15 mg/kg dose of oral dexamethasone Control (N = 50): single dose of oral placebo
Outcomes	Reattendance at the emergency department with croup
Notes	Funding source: no external funding
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	Unclear risk	Quote: "Treatments were given double blind" Comment: no further explanation given. Unclear who was blinded. Subjective outcomes
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: no description of a third‐party outcome assessor. Carried over judgement from blinding of participants and personnel
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: 4% (N = 4) lost to follow‐up. Equal between groups
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	Unclear risk	Comment: at least 1 domain judged as unclear risk, and no domains judged as high risk.