Richter 1998.

Methods	Parallel design, 2 arms Single‐centre, conducted in the UK (affiliation: Royal Alexandra Children's Hospital Brighton)
Participants	Inpatients Inclusion/exclusion criteria Inclusion criteria: age < 12 mo.; no history of wheezing; hospitalised with clinical features of bronchiolitis (tachypnoea, recession, wheezing, crepitations) Exclusion criteria: congenital abnormality; pre‐existing pulmonary disease; immune deficiency; need for assisted ventilation Participant characteristics All groups Sample size: randomised (N): 40, analysed ‐ trial primary outcomes (N): 39 (ITT with available case analysis was performed), analysed ‐ review primary outcomes (N): 40 (ITT with all data was performed) GROUP 1 Sample size: randomised (N): 21, analysed ‐ trial primary outcomes (N): 20, analysed ‐ review primary outcomes (N): 21 Age: 4.08 (median); 1.1 to 10.15 (range) months Males, N (%): 12 (57) RSV status: 16 (76) positive Atopic status: 18 (86) present (family) GROUP 2 Sample size: randomised (N): 19, analysed ‐ trial primary outcomes (N): 19, analysed ‐ review primary outcomes (N): 19 Age: 2.7 (median); 0.9 to 7.82 (range) months Males, N (%): 10 (52.6) RSV status: 17 (89) positive Atopic status: 12 (63) present (family)
Interventions	GROUP 1 (with glucocorticoid) Drug name: budesonide Dose: 1 mg in 2 mL then 0.5 mg in 2 mL Mode of administration: nebulised with O2, flow 6 L/minute Timing/duration: 1 mg/2mL ‐ twice daily for 5 d; 0.5 mg/2 mL ‐ 2 x daily for 6 weeks GROUP 2 Drug name: placebo Dose: 2 mL 0.9% saline Mode of administration: nebulised with O2, flow 6 L/minute Timing/duration: twice daily for 6 weeks Additional co‐interventions for all groups: no restrictions on use of other drug treatments Protocolised use of bronchodilators with glucocorticoids: no
Outcomes	Primary outcome Clinical scale adapted from Wesley et al, based on respiratory rate, O2 concentration required to keep O2 > 92%, wheeze, degree of recession, and need for IV fluids or nasogastric tube feeding (at 48 hours; other time points*) Clinical scale*: RDAI, 17‐point score based on wheezing and retractions (at 4 hours; other time points*) Outcome used to calculate sample size Wheezing episodes in the early months after bronchiolitis (no specific time point or definition) Secondary outcomes Duration and maximum requirements of O2 therapy; LOS; hospital re‐admission (6 mo.); symptoms (diary; based on Noble et al, daytime and nighttime cough and wheeze)#¶; inhaled bronchodilators#¶; length and growth rate# *time points: twice daily until discharge, 48 hours #time points: daily until 6 weeks ¶time points: until 6 months, when symptomatic and by 6‐week periods
Funding	Astra Clinical Research Unit and Rockinghorse Appeal
Notes	Study did not report any study‐level subgroup analyses This study contributed to the following comparisons in this review: steroid versus placebo
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised; no further information provided
Allocation concealment (selection bias)	Unclear risk	Randomisation details held by hospital pharmacy
Blinding (performance bias and detection bias) Health care use ((re)admissions, LOS, return visits)	Unclear risk	Double‐blind; "Throughout the study, the investigators, nursing and medical staff, and parents were unaware to which treatment group infants had been assigned"; "both budesonide and placebo were supplied in plastic repsules prepared by Astra pharmaceuticals"
Blinding (performance bias and detection bias) Clinical parameters (severity scales, SpO2, respiratory and heart rate)	Unclear risk	Double‐blind; "Throughout the study, the investigators, nursing and medical staff, and parents were unaware to which treatment group infants had been assigned"; "both budesonide and placebo were supplied in plastic repsules prepared by Astra pharmaceuticals"
Blinding (performance bias and detection bias) Other outcomes (adverse events, others)	Unclear risk	Double‐blind; "Throughout the study, the investigators, nursing and medical staff, and parents were unaware to which treatment group infants had been assigned"; "both budesonide and placebo were supplied in plastic repsules prepared by Astra pharmaceuticals"
Incomplete outcome data (attrition bias) Health care use ((re)admissions, LOS, return visits)	Low risk	1 participant with missing outcome data
Incomplete outcome data (attrition bias) Clinical parameters (severity scales, SpO2, respiratory and heart rate)	Low risk	1 participant with missing outcome data
Incomplete outcome data (attrition bias) Other outcomes (adverse events, others)	Low risk	1 participant with missing outcome data
Selective reporting (reporting bias)	Unclear risk	Not all outcomes reported are specified in methods
Other bias	Low risk	No significant baseline imbalances; no other sources of bias
Overall risk of bias	Unclear risk	> 1 domain as unclear risk of bias