Klassen 1996.
| Study characteristics | ||
| Methods | Randomised, double‐blind controlled trial | |
| Participants |
Study period: October 1993 to April 1994 Setting: emergency department of the Children's Hospital of Eastern Ontario, Canada Inclusion criteria: children aged 3 months to 5 years presenting to the emergency department with mild to moderate croup (hoarseness, inspiratory stridor, barking cough) and a modified Westley croup score ≥ 3 after at least 15 minutes of mist therapy Exclusion criteria: diagnosis of epiglottitis, chronic upper or lower airway disease (excluding asthma), severe croup (modified Westley croup score ≥ 8); received glucocorticoids within the previous 2 weeks; needed immediate racaemic epinephrine on arrival Baseline demographics (N = 50):
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| Interventions | All children received a single 0.60 mg/kg dose of oral dexamethasone upon entry into the study. Treatment (N = 25): single 2 mg (4 mL) dose of nebulised budesonide Control (N = 25): single 4 mL dose of placebo (0.9% saline solution) Both treatment and control delivered by an updraft nebuliser with a continuous flow of oxygen at a rate of 5 to 6 L/min. |
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| Outcomes | Change in modified Westley croup score from baseline to 4 hours; admissions to the hospital; 2‐point improvement in croup score at 4 hours; use of epinephrine, use of supplemental glucocorticoids, and use of mist tent | |
| Notes | Funding source: Ontario Ministry of Health | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Randomization was performed in blocks of 10 by the pharmacy department, using a random numbers table" |
| Allocation concealment (selection bias) | Low risk | Quote: "Randomization was performed... by the pharmacy department"; "the pharmacy provided both budesonide and normal saline in opaque, brown syringes."; "the randomization code was revealed only after all patients had completed the trial" |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote: "Budesonide is slightly opaque; therefore, to conceal its identity, the pharmacy provided both budesonide and normal saline in opaque, brown syringes. The research assistants placed the drugs directly into an opaque nebulizer reservoir. Once nebulized, the drugs were indistinguishable by sight and smell." "Both the research assistants and the physicians caring for the patients in the emergency department were blinded to treatment assignment" |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "Budesonide is slightly opaque; therefore, to conceal its identity, the pharmacy provided both budesonide and normal saline in opaque, brown syringes. The research assistants placed the drugs directly into an opaque nebulizer reservoir. Once nebulized, the drugs were indistinguishable by sight and smell." "Both the research assistants and the physicians caring for the patients in the emergency department were blinded to treatment assignment" |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Comment: 2% (N = 1) in the placebo group required racaemic epinephrine and was excluded; 2% (N = 1) lost to follow‐up in the treatment group because parent could not be contacted for follow‐up |
| Selective reporting (reporting bias) | Unclear risk | Comment: no protocol identified. All prespecified outcomes in the methods appeared in the results. |
| Other bias | Unclear risk | Comment: 33 children were not enrolled because the study team was not contacted; this could potentially have biased participant selection |
| Overall risk of bias All outcomes | Unclear risk | Comment: at least 1 domain judged as unclear risk, and no domains judged as high risk |