de Alba Romero 1998.

Methods	Randomised controlled trial; single centre; Spain
Participants	N = 80. Inclusion criteria were BW ≥ 1200 g, with suspected sepsis. Exclusion criteria were known renal impairment (serum creatinine > 1.2 mg/dl), severe neonatal asphyxia and unavailability of blood samples. 'Once a day' gentamicin: N = 33. 'Multiple doses a day' gentamicin: N = 32. Mean gestational age in 'once a day' gentamicin group was 35.5 ± 3.4 weeks vs 36.2 ± 2.9 weeks in 'multiple doses a day' group. Mean BW in 'once a day' group was 2407 ± 757 g vs 2525 ± 730 g in 'multiple doses a day' group.
Interventions	'Once a day' gentamicin group were given gentamicin at 5 mg/kg/dose once every 24 h. 'Multiple doses a day' gentamicin group were given gentamicin at 2.5 mg/kg/dose every 12 h. Gentamicin was given as intravenous infusion over 60 min. All patients received ampicillin concomitantly.
Outcomes	The peak serum gentamicin level was measured 60 min after completion of the infusion on the 4th day of treatment. Trough levels were measured immediately before the administration of the dose on 4th day of treatment. Other outcomes that were measured were urinary N‐Acetyl‐Beta‐D‐glucosaminidase:creatinine ratio within the first 2 days and on the 7th day of treatment, serum creatinine on the 4th day of treatment.
Notes	Additional information and methodology were clarified by the authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Neonates were randomized to treatment with gentamicin 5mg/kg either once daily, or in twice divided doses." The sequence generation process not described.
Allocation concealment (selection bias)	Low risk	Using sealed envelopes.
Blinding (performance bias and detection bias) All outcomes	Low risk	Outcome assessors were blinded to the intervention.
Incomplete outcome data (attrition bias) All outcomes	High risk	Only 65 out of the 80 completed the study.
Selective reporting (reporting bias)	Unclear risk	"Clinical efficacy was determined in both groups by clinical evaluation by customary evaluations" It is unclear how this was done.
Other bias	Low risk	Appears to be free of other biases.