Efficacy Endpoints: Return visits and/or (re)admissions; required for additional treatment (rescue therapy)
Harm Endpoints: Medication side effects
Narrative: Croup is a self-limiting upper airway disease in children. However, croup accounts for a high number of physician visits and hospital admissions. It accounts for an annual incidence of 1.5 to 6% in children less than six years of age. Admission rates vary from 1.5% to 31%.
This Cochrane review has 41 trials, all parallel design, occurring in the inpatient and outpatient setting. Dexamethosone is the most commonly evaluated glucocorticoid in this Cochrane review. Other glucocorticoids are budesonide, prednisone, and fluticasone.
Ten trials were examined for return visits and/or (re)admission rates from 1679 enrolled patients. The authors found the rates were reduced with glucocorticoids therapy, as compared to placebo (ARR = 9.2%, NNT = 11).
There were 17 trials that assessed the need for rescue therapy, such as intubation/tracheostomy, antibiotic use, additional glucocorticoid use, or mist tent use. While there was no reduction in these rescue therapy endpoints, a reduction in epinephrine as a rescue therapy was noted, with an absolute risk reduction of 10% (NNT = 10).
Caveats: In the Cochrane review, glucocorticoid has been shown to reduce the revisits and/or (re)admission rates and to decrease epinephrine use as a rescue therapy. The seven trials in the ED show the most benefit of glucocorticoid, where the absolute risk difference is 10% (NNT = 10). In the inpatient setting this absolute risk difference was 6.8% (NNT = 15). The 9.2% absolute benefit in need for readmission (NNT=11) is impressive, but this is based on a 21% overall rate of readmission in children in the control groups in this review. The actual benefit for a child will depend upon how often croup children are readmitted at baseline in one’s institution. The Cochrane authors note that in their group of studies the average readmission rate among institutions was roughly 12%, which would suggest an average NNT of 17.
The Cochrane review examined other outcome measures, such as length of stay and clinical severity. The cumulative length of stay was shortened by glucocorticoids by just over 11 hours in the combined inpatient (8 trials) and outpatient (1 trial) trials. Leipzig (1979) was the sole ED trial, however these study patients were admitted to the inpatient floors.
Finally, glucocorticoid treatment reduced clinical severity as measured by Westley scores. Children have a better clinical outcome according to the Westley score at the 6-hour and 12-hour mark (-1.2 and -1.9 points, respectively). A score reduction of 1 unit from baseline is deemed to be clinically significant.
Overall, the Cochrane review suggests that 5 patients would need to be treated with glucocorticoid for 1 patient to experience some measurable clinical benefit. The benefits are lower Westley score, fewer visits and/or (re)admission, decreased length of stay, or decreased usage of epinephrine as rescue therapy.
Author: Jeffrey Hom, MD, MPH
Published/Updated: February 15, 2011
The title bar is color-coded with our overall recommendation.
If you have suggestions, requests, or questions about a particular NNT review, please send us a message and we’ll try to address it as soon as possible.