Hammerberg 1989.

Study characteristics
Methods	Randomised controlled trial Duration: at the discretion of the attending neonatologist. Maximum duration 10 days Date: NA Location: NICU in Canada
Participants	396 infants suspected of early‐onset sepsis Inclusion criteria: had combination of risk factors or clinical signs (or both) compatible with sepsis; aged < 7 days of life Gender (boy/girl): NA Age: median gestational age 31.5 weeks. 97% were < 72 hours at randomisation. Exclusion criteria: previously received antibiotics, had underlying congenital conditions incompatible with life or were known to be septic.
Interventions	Intervention 1: piperacillin 50 mg/kg and placebo (5% dextrose in water) every 12 hours Intervention 2: ampicillin 50 mg/kg and amikacin 7.5 mg/kg every 12 hours Co‐interventions: not described
Outcomes	Primary outcome All‐cause mortality Secondary outcomes Mortality due to infection Duration of treatment Renal impairment (nephrotoxicity) defined as > 100 μmol/L Hepatic impairment defined as total serum bilirubin > 20 μmol/L Follow‐up Not described
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Used computer‐generated randomised sequence.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Described as being blinded and used placebo.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear whether outcome assessors were blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts.
Selective reporting (reporting bias)	Low risk	Reported mortality.
Other bias	Low risk	No other bias observed.