Klig 1997.

Methods	A prospective, randomised, non‐blinded clinical trial with blinded outcome assessors Comparison of IM dexamethasone versus oral prednisone Randomization was stated but method was not described. Allocation concealment was accomplished using sealed opaque packets.
Participants	Patients, who had 2 prior episodes of wheezing and were treated with beta‐2‐adrenergic agents, presented to ED with mild to moderate wheezing and did not require admission to hospital Enrolment of patients was based on the pulmonary index (0 to 3), assessment of a clinical score for asthma, and pulse oximetry on arrival to ED. Ages: enrolled patients 3 to 16 years. Mean age of IM corticosteroid group: 82 months (SD: 46). Mean age of oral corticosteroid group: 63 months (SD: 36) Reported enrolling patients with mild‐moderate exacerbations. Unable to assess exacerbation severity based on baseline PEF Patients were excluded from study if they received corticosteroids within the last month or were hospitalised for asthma treatment within the last 2 months prior to the study. Set in United States Sex: 24 men, 18 women
Interventions	Interventions: single IM dose of dexamethasone (0.3 mg/kg, maximum of 15 mg) versus oral prednisone (2 mg/kg/day, maximum of 100 mg) for 3 days. No placebo treatment was provided. Co‐interventions in the ED: nebulized albuterol (5 mg/mL solution) 0.5 mL in 2 mL of normal saline by oxygen face mask set at 6 L of flow every 20 to 30 min Co‐interventions at discharge: albuterol (liquid, nebulized, or metered dose inhaler (MDI) 4 times a day until follow‐up was completed Additional systemic corticosteroids were not permitted.
Outcomes	Followed up on day 5 either by assessment in out‐patient clinic or via telephone interview Primary outcome: symptomatic improvement on follow‐up 5 days after initial treatment and relapse and/or clinical deterioration within 5 days after discharge from ED (relapse was defined as the worsening of respiratory symptoms after discharge from ED, visits to the out‐patient clinic or emergency department, or admission to the hospital) Secondary outcome: pulmonary index scores on discharge from ED, and further corticosteroid use after the follow‐up evaluation
Notes	Author was contacted and provided clarification on allocation concealment and source of funding No registered protocol was identified
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided on how patients were randomised. Study authors confirmed via personal communication that randomisation was in blocks. Quote (p. 421): "Patients were randomly assigned by sealed packets to receive either oral prednisone tablets 2 mg/kg or IM dexamethasone 0.3 mg/kg." Personal communication: "Randomization was in blocks."
Allocation concealment (selection bias)	Low risk	Allocation concealment ensured via sealed packets. Study authors confirmed via personal communication that the sealed packets were opaque. Quote (p. 421): "Patients were randomly assigned by sealed packets to receive either oral prednisone tablets 2 mg/kg or IM dexamethasone 0.3 mg/kg." Personal communication: "Sealed packets were opaque"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Non‐blinded study. Quote (p. 421): "The assigned corticosteroid was administered in an unblinded manner immediately after enrolment in the study."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors blinded. Stated that Investigators (Physicians) were blinded to patient's treatment. Quote (p. 422): "Patient follow‐up was conducted on the fifth day after discharge from the PED by a physician blinded to group assignment."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Patient exclusions balanced between groups. Quote (p. 422): "Forty‐four patients participated in the pilot study of whom 23 received a single dose of IM dexamethasone and 21 received 3 days of oral prednisone. Two patients from the IM dexamethasone group were admitted to the hospital shortly after enrolment and therefore were removed from the study. The remaining 42 patients were discharged to home, resulting in an even distribution between the IM dexamethasone and oral prednisone groups."
Selective reporting (reporting bias)	Unclear risk	No protocol available.
Other bias	Low risk	The study appears to be free of other sources of bias. Study authors confirmed via personnel communication that the study was not funded. Personal communication: "Study was funded via supplies only (decadron from Merck Pharmaceuticals)."