Bullock 1988.

Methods	Randomized, controlled Method of randomisation: unclear Kind of shunt: ventriculoperitoneal shunts Location: South Africa Follow‐up: 90 days after surgery Duration: unclear
Participants	Inclusion: patients undergoing "clean" neurosurgical operative procedures Exclusion: patients with known piperacillin hypersensitivity or allergy, patients who had undergone a neurosurgical operation within a month prior to study and patients who had received any antibiotic therapy within 7 days prior to the study Treatment: 48, control 48
Interventions	Piperacillin IV 35 mg/kg 30 to 60 minutes prior to surgery and 2 doses at 6 and 12 hours postoperatively Control: placebo (saline)
Outcomes	Sepsis (wound, meningitis) 3 cases of sepsis occurred within 22 days after surgery
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Low risk	"Allocation of antibiotic or placebo was carried out using a random number list"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Investigators remained blinded until the end of the study"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	20 participants were excluded, exclusions were well described. A Chi² test was performed in order to check for statistically significant differences between exclusions in the treatment and placebo group. No statistical difference was found
Selective reporting (reporting bias)	Unclear risk	Not well described
Other bias	Unclear risk	35 protocol deviations occurred, which could cause bias in outcome, even when statistical analysis both including and excluding these protocol deviations show no statistical differences