Table A Characteristics of randomised controlled trials of treatments for croup included in the meta-analysis

Trial	No of patients	Setting	Intervention	Control	Outcomes	Jadad score*	Allocation Concealment†
Cruz 1995^w1	45	Accident and emergency	Intramuscular dexamethasone 0.6 mg/kg	Placebo	Clinical improvement, visits to the doctor, readmissions	2	1
Eden 1964^w2	50	Hospital	Intramuscular methylprednisolone 4 mg/kg/day	Placebo	Clinical improvement, use of mist tent and antibiotics	3	3
Eden 1967^w3	50	Hospital	Intramuscular dexamethasone 0.4 mg/kg/day	Placebo	Stridor, dyspnoea, retractions, and cyanosis	3	3
Fitzgerald 1996^w4	67	Hospital	Nebulised budesonide 2 mg	L-epinephrine 4 mg	Modified Westley croup score, use of epinephrine and steroids, length of hospital stay	3	2
Geelhoed 1995^w5	80	Accident and emergency	Nebulised budesonide 2 mg Oral dexamethasone 0.6 mg/kg	Placebo	Stridor and retractions, use of epinephrine, length of stay in observation unit	3	3
Geelhoed 1995a^w6	60	Accident and emergency	Oral dexamethasone 0.6 mg/kg	Oral dexamethasone 0.3 mg/kg	Stridor and retractions, use of epinephrine, length of stay in observation unit	3	3
Geelhoed 1995b^w6	60	Accident and emergency	Oral dexamethasone 0.3 mg/kg	Oral dexamethasone 0.15 mg/kg	Proportion hospitalised in 24 hours
Geelhoed 1996^w7	100	Accident and emergency	Oral dexamethasone 0.15 mg/kg	Placebo	Return to accident and emergency department for symptoms of croup	2	3
Godden 1997^w8	87	Hospital	Nebulised budesonide 2 mg initially, then 1 mg every 12 hours during hospitalization	Placebo	Modified Westley croup score, use of epinephrine and intubation, length of stay	4	3
Husby 1993^w9	37	Hospital	Nebulised budesonide 1mg/dose for two doses 30 minutes apart	Placebo	Modified Westley croup score, use of antibiotics	3	3
James 1969^w10	88	Hospital	Intramuscular dexamethasone 4 -12 mg	Placebo	Use of mist tent or antibiotics, tracheostomy	4	3
Johnson 1996^w11	55	Accident and emergency	Nebulised dexamethasone 10-20 mg	Placebo	Modified Westley croup score, admission rate	4	1
Johnson 1998^w12	144	Accident and emergency	Nebulised budesonide 4 mg	Placebo	Westley croup score, use of epinephrine and mist treatment	2	1
Klassen 1998^w13	198	Accident and emergency	Nebulised budesonide 2 mg Nebulised budesonide 2 mg and oral dexamethasone 0.6 mg/kg	Oral dexamethasone 0.6 mg/kg	Westley croup score, use of epinephrine and steroids, length of stay, admission rates	5	1
Klassen 1994^w14	54	Accident and emergency	Nebulised budesonide 2 mg	Placebo	Westley croup score, use of epinephrine and steroids, length of stay, admission rates	5	1
Klassen 1996^w15	50	Accident and emergency	Nebulised budesonide 2 mg and oral dexamethasone 0.6 mg/kg	Oral dexamethasone 0.6 mg/kg	Westley croup score, use of epinephrine and steroids, length of stay, admission rates	5	1
Koren 1983^w16	78	Hospital	Intramuscular dexamethasone 0.6 mg/kg	Placebo	Respiratory rate	2	3
Kuusela 1988^w17	72	Hospital	Intramuscular dexamethasone 0.6 mg/kg, Intramuscular dexamethasone 0.6 mg/kg, and L-epinephrine 2.25% 0.25 ml/kg	L-epinephrine 2.25% 0.25 ml/kg	Dyspnoea and cough, length of stay	3	1
Leipzig 1979^w18	30	Hospital	Intramuscular dexamethasone 0.3 mg/kg/dose for two doses	Placebo	Stridor, cyanosis, retractions, respiratory rate, heart rate Use of epinephrine and intubation Length of stay	3	3
Martinez 1993^w19	66	Hospital	L-epinephrine, L-epinephrine and intramuscular dexamethasone 0.5 mg/kg, intramuscular dexamethasone 0.5 mg/kg	Placebo	Stridor, dyspnoea, cough, cyanosis, use of mist treatment	3	1
Massicotte 1973^w20	42	Hospital	Intravenous methylprednisolone 4 mg at 0, 4, and 8 hours	Placebo	Clinical improvement, use of antibiotics and tracheostomy	4	1
Muhlendahl 1982^w21	406	Hospital	Oral dexamethasone 6 mg	Placebo	Westley croup score, clinical improvement, tracheostomy, length of stay	2	3
Skowron 1966^w22	200	Hospital	Subcutaneous dexamethasone 4 or 6 mg	Placebo	Use of mist treatment, antibiotics, tracheostomy	2	3
Super 1989^w23	29	Hospital	Intramuscular dexamethasone 0.6 mg/kg	Placebo	Westley croup score, clinical improvement, use of epinephrine, steroids, mist treatment, length of stay	5	1
Tibballs 1992^w24	73	Intensive care unit (intubated patients)	Nasogastric prednisolone 2 mg/kg/day until 24 hours after extubation	Placebo	Length of intubation reintubation rate	4	1

*Five point scale.

†Scored as 1=adequate, 2=inadequate, 3=unclear.

References:

w1 Cruz MN, Stewart G, Rosenberg N. Use of dexamethasone in the outpatient management of acute laryngotracheitis. Pediatrics 1995;96:220-3.

w2 Eden AN, Larkin VP. Corticosteroid treatment of croup. Pediatrics 1964;33:768-9.

w3 Eden AN, Kaufman A, Yu R. Corticosteroids and croup: controlled double-blind study. JAMA 1967;200:403-4.

w4 Fitzgerald D, Mellis C, Johnson M, Allen H, Cooper P, Van Asperen P. Nebulized budesonide is as effective as nebulized adrenaline in moderately severe croup. Pediatrics 1996;97:722-5.

w5 Geelhoed GC, Macdonald WB. Oral and inhaled steroids in croup: a randomized, placebo-controlled trial. Pediatr Pulmonol 1995;20:355-61.

w6 Geelhoed GC, Macdonald WB. Oral dexamethasone in the treatment of croup: 0.15 mg/kg versus 0.3 mg/kg versus 0.6 mg/kg. Pediatr Pulmonol 1995;20:362-8.

w7 Geelhoed GC, Turner J, Macdonald WB. Efficacy of a small single dose of oral dexamethasone for outpatient croup: a double blind placebo controlled clinical trial. BMJ 1996;313:140-2.

w8 Godden CW, Campbell MJ, Hussey M, Cogswell JJ. Double blind placebo controlled trial of nebulised budesonide for croup. Arch Dis Child 1997;76:155-8.

w9 Husby S, Agertoft L, Mortensen S, Pedersen S. Treatment of croup with nebulised steroid (budesonide): a double blind, placebo controlled study. Arch Dis Child 1993;68:352-5.

w10 James JA. Dexamethasone in croup: a controlled study. Am J Dis Child 1969;117:511-6.

w11 Johnson DW, Schuh S, Koren G, Jaffe DM. Outpatient treatment of croup with nebulized dexamethasone. Arch Pediatr Adolesc Med 1996;150:349-55.

w12 Johnson DW, Jacobson S, Edney PC, Hadfield P, Mundy ME, Schuh S. A comparison of nebulized budesonide, intramuscular dexamethasone, and placebo for moderately severe croup. N Engl J Med 1998;339:498-503.

w13 Klassen TP, Craig WR, Moher D, Osmond MH, Pasterkamp H, Sutcliffe T, et al. Nebulized budesonide and oral dexamethasone for treatment of croup: a randomized controlled trial. JAMA 1998;279:1629-32.

w14 Klassen TP, Feldman ME, Watters LK, Sutcliffe T, Rowe PC. Nebulized budesonide for children with mild-to-moderate croup. N Engl J Med 1994;331:285-9.

w15 Klassen TP, Watters LK, Feldman ME, Sutcliffe T, Rowe PC. The efficacy of budesonide in dexamethasone-treated outpatients with croup. Pediatrics 1996;97:463-6.

w16 Koren GF. Corticosteroid treatment of laryngotracheitis v spasmodic croup in children. Am J Dis Child 1983;137:941-44.

w17 Kuusela AL, Vesikari T. A randomized double-blind, placebo-controlled trial of dexamethasone and racemic epinephrine in the treatment of croup. Acta Paediatr Scand 1988;77:99-104.

w18 Leipzig B, Oski FA, Cummings CW, Stockman JA, Swender P. A prospective randomized study to determine the efficacy of steroids in treatment of croup. J Pediatr 1979;94:194-6.

w19 Martinez Fernandez A, Sanchez Gonzalez E, Rica Etxebarria I, Echaniz Urcelay I, Alonso Diez M, Vilella Ciriza M, et al. [Randomized double-blind study of treatment of croup with adrenaline and/or dexamethasone in children]. Anales Españoles de Pediatría 1993;38:29-32. (In Spanish.)

w20 Massicote P, Tetreault L. [Evaluation of methyl-prednisolone in the treatment of acute laryngitis in children]. Union Med Can 1973;102:2064-72. (In French.)

w21 Von Muhlendahl KE, Kahn D, Spohr HL, Dressler F. Steroid treatment in pseudo-croup. Helv Paediatr Acta 1982;37:431-6.

w22 Skowron PN, Turner JA, McNaughton GA. The use of corticosteroid (dexamethasone) in the treatment of acute laryngotracheitis. Can Med Assoc J 1966;94:528-31.

w23 Super DM, Cartelli NA, Brooks LJ, Lembo RM, Kumar ML. A prospective randomized double-blind study to evaluate the effect of dexamethasone in acute laryngotracheitis. J Pediatr 1989;115:323-9.

w24 Tibballs J, Shann FA, Landau LI. Placebo-controlled trial of prednisolone in children intubated for croup. Lancet 1992;340:745-8.