Allison Gates, Michelle Gates, Ben Vandermeer, Cydney Johnson, Lisa Hartling, David W Johnson, Terry P Klassen

Glucocorticoids are commonly used for croup in children. This is an update of a Cochrane Review published in 1999 and previously updated in 2004 and 2011. To examine the effects of glucocorticoids for the treatment of croup in children aged 0 to 18 years. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 2, 2018), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, Ovid MEDLINE Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Ovid MEDLINE (1946 to 3 April 2018), and Embase (Ovid) (1996 to 3 April 2018, week 14), and the trials registers ClinicalTrials.gov (3 April 2018) and the World Health Organization International Clinical Trials Registry Platform (ICTRP, 3 April 2018). We scanned the reference lists of relevant systematic reviews and of the included studies. We included randomised controlled trials (RCTs) that investigated children aged 0 to 18 years with croup and measured the effects of glucocorticoids, alone or in combination, compared to placebo or another pharmacologic treatment. The studies needed to report at least one of our primary or secondary outcomes: change in croup score; return visits, (re)admissions or both; length of stay; patient improvement; use of additional treatments; and adverse events. One author extracted data from each study and another verified the extraction. We entered the data into Review Manager 5 for meta-analysis. Two review authors independently assessed risk of bias for each study using the Cochrane 'Risk of bias' tool and the certainty of the body of evidence for the primary outcomes using the GRADE approach. We added five new RCTs with 330 children. This review now includes 43 RCTs with a total of 4565 children. We assessed most (98%) studies as at high or unclear risk of bias. Compared to placebo, glucocorticoids improved symptoms of croup at two hours (standardised mean difference (SMD) -0.65, 95% confidence interval (CI) -1.13 to -0.18; 7 RCTs; 426 children; moderate-certainty evidence), and the effect lasted for at least 24 hours (SMD -0.86, 95% CI -1.40 to -0.31; 8 RCTs; 351 children; low-certainty evidence). Compared to placebo, glucocorticoids reduced the rate of return visits or (re)admissions or both (risk ratio 0.52, 95% CI 0.36 to 0.75; 10 RCTs; 1679 children; moderate-certainty evidence). Glucocorticoid treatment reduced the length of stay in hospital by about 15 hours (mean difference -14.90, 95% CI -23.58 to -6.22; 8 RCTs; 476 children). Serious adverse events were infrequent. Publication bias was not evident. Uncertainty remains with regard to the optimal type, dose, and mode of administration of glucocorticoids for reducing croup symptoms in children. Glucocorticoids reduced symptoms of croup at two hours, shortened hospital stays, and reduced the rate of return visits to care. Our conclusions have changed, as the previous version of this review reported that glucocorticoids reduced symptoms of croup within six hours.