Schuckman 1998.

Methods	A prospective, randomised, double‐blinded, placebo‐controlled clinical trial Comparison of IM triamcinolone versus oral prednisone Randomization was accomplished using computer‐generated random numbers. Allocation concealment was reported and discussed as pharmacy controlled by using computerized generated set of numbers to package medications and placebo into sequentially numbered kits.
Participants	Patients presented to the ED with an asthma exacerbation that had an initial PEF < 350 L/min and did not require admission to hospital on ED presentation The diagnosis of asthma was according to the American Thoracic Society criteria (1987) Patients were excluded from study if had received corticosteroids within 2 weeks prior to ED presentation or were unable or unwilling to attend follow‐up evaluation. Ages: Enrolled patients 18 to 50 years. Mean age of IM corticosteroid group: 31 years (SD: 9). Mean age of oral corticosteroid group: 32 years (SD: 9) Exacerbation severity not reported. Exacerbation severity estimated as mild/moderate based on baseline PEF Set in United States Sex: 47 mean, 107 women
Interventions	Interventions: single IM dose of triamcinolone (40 mg) followed by 10 placebo tablets twice daily for 5 days versus oral prednisone (20 mg twice daily) for 5 days, in addition to a single IM placebo injection. Placebo was provided for both groups Co‐interventions in the ED: albuterol, oral or IV corticosteroids Co‐interventions at discharge: beta‐2‐agonist MDI at least 4 times daily, albuterol MDI, regular medications including those for asthma including ICS, cromolyn sodium, ipratropium bromide MDI, and oral antibiotics
Outcomes	Patients were followed up 7 to 10 days after ED enrolment. Primary outcome: relapse (defined as an unscheduled or emergency visit to a physician’s office to the ED for persistent or worsening symptoms of asthma within 7 days of the initial ED visit) Secondary outcome: difference in symptom severity on the fifth day post‐discharge Compliance (defined as having an empty pill bottles at the follow‐up visit) PEF
Notes	Author was contacted and provided clarification on the methodology of blinding and outcome data. Was unable to provide copy of the study protocol. No registered protocol was identified.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation completed via computer generated set of random numbers. Quote (p. 334): "A computer‐generated set of random numbers was used by the hospital pharmacy to package the active medications and placebos into sequentially numbered kits."
Allocation concealment (selection bias)	Low risk	Pharmacy controlled allocation concealment. Medications and placebos packaged in sequentially numbered kits. Quote (p. 334): "A computer‐generated set of random numbers was used by the hospital pharmacy to package the active medications and placebos into sequentially numbered kits."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blinded study. Study authors confirmed via personnel communication that the study medications were indistinguishable from each other. Personal communication: "Syringes were prefilled and tablets looked similar for placebo and prednisone. Each patient received injection and pill bottle. They brought their bottle to follow‐up."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors (physicians) were blinded to the patient's group assignment. Quote (p. 335): "Physicians evaluating patients at follow‐up remained blinded to drug group assignment."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Detailed information on study attrition provided in flow diagram provided (p. 337). Excluded patients balanced between groups. Quote (p. 335‐6): "We approached 186 patients who were potentially eligible; 15 (9%) refused to participate, and 3 (2%) resided out of town and could not return for follow‐up. A total of 168 patients were enrolled, 82 in the triamcinolone group and 86 in the prednisone group. Fourteen patients were withdrawn from analysis: 6 (3 in each group) for protocol violations because the patient was older than 50 years of age, and 8 (1 in the triamcinolone group and 7 in the prednisone group) because they were lost to follow‐up. The final study population was 154 patients, 78 in the triamcinolone group and 76 in the prednisone group."
Selective reporting (reporting bias)	Unclear risk	No protocol available.
Other bias	Low risk	No other potential source of bias found. Source of funding provided. Quote (p. 333): "Research supported by the Summa Health System Foundation."

Abbreviations

ED: emergency department

FEV1: forced expiratory volume

FVC: forced vital capacity

ICS: inhaled corticosteroids

IM: intramuscular

MDI: metered dose inhaler

PEF: peak expiratory flow

IV: intravenous

SD: standard deviation

SEM: standard error of mean

IQR: interquartile range