Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Change in croup score
Systematic review	28 children with moderate croup (excluding spasmodic croup) in an inpatient setting Data from 1 RCT	Mean between-group change from baseline croup score 30 minutes –2.28 with nebulised racemic adrenaline (14 children) –2.84 with nebulised L- adrenaline (14 children)	SMD 0.33 95% CI –0.42 to +1.08		Not significant
Systematic review	28 children with moderate croup (excluding spasmodic croup) in an inpatient setting Data from 1 RCT	Mean between-group change from baseline croup score 2 hours –0.65 with nebulised racemic adrenaline (14 children) –2.2 with nebulised L-adrenaline (14 children)	SMD 0.87 95% CI 0.09 to 1.65	Effect size not calculated	L-adrenaline