Table 2: Relative heterogeneity of the included studies.

Author Patient Group and Age Study Design Outcomes Key Results Study Weaknesses
[52] Sparrow and Geelhoed,
2006.
Children aged 3 months to 142 months old presenting to a single emergency department with mild to moderate croup. Randomization and blinding
Double blind, randomised equivalence study.
Sample size and attrition
133. No attrition
Medication dosages
Patients received a single dose of 0.15 mg/kg dexamethasone 0.6 dexamethasone or 1 mg/kg prednisolone.
Lengths of time of administration
Single dose of prednisolone, 1 mg/kg, matched for potency with a single dose of dexamethasone in children with mild to moderate croup.
Primary outcome was the magnitude and rate of reduction in Westley croup score.
Clinical observations at 30 minutes after administration of steroid; hourly for the next four hours and four hourly thereafter until discharge. Criteria for discharge home were minimal stridor or chest wall retractions—that is, a croup score of 1 or 0.
Re-attendance at medical care within 7-10 days.
Responses to treatment:
Five out of 68 (7%) children who had received dexamethasone returned for medical care versus 19/65 (29%) children who had received prednisolone.
No significant difference between the three groups in magnitude or rate of Westley score reduction.
Included patients up to the age of 12 years, although very uncommon for older children to be affected.
Exclusion criteria included prior administration of steroids, non-English speakers and no access to telephone. Small numbers.
[53] Fifoot and Ting,
2007
Children 6 months to 6 years presenting to a single emergency department with mild or moderate croup Randomization and blinding
Double blind, randomised trial.
Sample size and attrition
99 children with 86 patients followed up by telephone (87%).
Medication dosages
Patients were randomised to receive 1 mg/kg prednisolone, 0.15 mg/kg dexamethasone or 0.6 mg/kg dexamethasone.
Lengths of time of administration
Single dose.
Primary outcome measures were the magnitude and rate of reduction in Westley croup score, rate of return for medical care with ongoing croup, and further treatment with steroids in the week following index presentation. Secondary outcome measures were the proportion of subjects requiring admission or salvage therapy, such as nebulized adrenaline, during index presentation.
Follow-up by telephone interview at 7 days, Taussig score.
Responses to treatment
No significant difference in admission rates, duration of symptoms or attendances. No significant difference between treatment groups.
Small sample size. Large number of eligible patients not recruited. Primary outcome over short time period.
[54] Garbutt et al, 2013 Children aged 1-8 years presenting to primary care offices with mild or moderate croup in the USA. Randomization and blinding
Double blinded randomised comparison trial
Sample size and attrition
Eighty-seven children randomised with 98% follow up at 11 days.
Medication dosages and lengths of time of administration
Prednisolone 2mg/ kg per day for 3 days versus one dose of 0.6mg dexamethasone and two placebo doses
Additional health care within 11 days of randomization
assessed by self-report Telephone Out Patient score.
Secondary outcomes included: duration of croup symptoms; disturbed sleep; parental stress; adverse events including sleep problems, mood changes, headache or dizziness, nausea, stomach pain, and secondary infections.
No difference in outcomes of either group for child or parent. Small numbers.
People with no telephone and lacking English spoken language were excluded.
[55] Parker et al, 2004 Children aged 4 months to 11 years, median age 2 years presenting in an emergency department with mild or moderate croup Retrospective chart review.
Randomization and blinding
Not undertaken
Sample size and attrition
188 eligible for analysis from 814 patients coded as croup.
Medication dosages
1mg/kg prednisolone. Lengths of time of administration
Not specified but implicitly single dose only
How long stridor at rest persisted after administration of prednisolone 1mg /kg.
Westley and Geelhoed croup scores.
To determine whether children with mild croup
had a more rapid
resolution of stridor at rest.
Average length of time from SAR to cessation was 6.5 hours.
Children with mild croup improved quicker although this is reported as not clinically significant.
Retrospective chart reviews rely on completeness of contemporaneous data entry. Inter rater reliability reported as moderate. Lack of power calculation