Malley 1998.

Methods	Study design: parallel‐group RCT Setting: children's hospitals Duration: follow‐up 30 days after administration of study treatments
Participants	Location: USA Inclusion criteria < 24 months of age RSV detected from respiratory secretions within 48 hours before randomisation by direct fluorescent antibody, IFA, ELISA, or culture Intubation and conventional positive pressure ventilation for < 24 hours before randomisation Exclusion criteria Intubation for apnoea only and requiring < 30% fraction of inspired oxygen Significant cardiac abnormalities Diagnosis of immunodeficiency Extracorporeal membrane oxygenation or high‐frequency ventilation Receipt of systemic steroids within 3 weeks before randomisation unless administered for the current RSV illness within 48 h before intubation Use of oxygen for > 7 days in prior 3 months Baseline characteristics (N = 35) Median age (range), months: treatment: 3.2 (1.2 to 23.8); comparator: 1.7 (0.8 to 15.4) Proportion male: treatment: 59%; comparator: 72% Health status/disease severity: children required intubation and mechanical ventilation at study entry. 3 children (18%) in the treatment group and 3 children (17) in the comparator group had "significant chronic medical conditions at the time of randomization" (p. 1557).  For the children in the treatment group, this included congenital anomalies in 1 child; microcephaly, developmental delay, and a seizure disorder in a second child; and a third child was quadriplegic. For the children in the comparator group, this included trisomy 21 in 2 children and Pierre Robin syndrome in 1 child.
Interventions	Treatment (N = 17): intravenous palivizumab 15 mg/kg Comparator (N = 18): intravenous 0.9% saline
Outcomes	Reduction in tracheal RSV concentration from day 0 to day 1 and day 0 to day 2 RSV concentrations in nasal washes White blood cell counts in tracheal aspirates Days of hospitalisation Days of mechanical ventilation Total days of supplemental oxygen Death
Notes	This study was funded by the manufacturer of the immunoglobulin used in the study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: the method used to generate the allocation sequence is unclear. There was insufficient information to permit judgement.
Allocation concealment (selection bias)	Low risk	Quote: "The study was centrally randomized in blocks of six per site." (p. 1556) Comment: an adequate method to conceal the allocation sequence was likely used.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "All clinical and laboratory personnel, the participants, and families were blinded to the treatment assignment; the pharmacist at each site was unblinded." (p. 1556) Comment: it is likely that participants and caregivers were blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "All clinical and laboratory personnel, the participants, and families were blinded to the treatment assignment; the pharmacist at each site was unblinded." (p. 1556) Comment: it is likely that the personnel responsible for outcome data were blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "All 35 randomized children were included in all analyses for which appropriate data were available." (p. 1557) Comment: all randomised children had data for clinical outcomes.
Selective reporting (reporting bias)	Unclear risk	Comment: outcome data are reported for all outcomes specified in the methods section of the publication. However, without a trial protocol it is unclear whether other outcomes were measured but not reported based on the nature of the results.
Other bias	High risk	Quote: "Financial support: MedImmune, Inc." (p. 1555) Comment: the trial was supported by MedImmune (manufacturer of MEDI‐493). This may lead to bias in favour of the intervention group.