Haines 1982.

Methods	Randomised, controlled Method of randomisation: coin toss Kind of shunt: ventriculoperitoneal shunts Location: USA Follow‐up: 6 months Duration: unclear
Participants	Inclusion: children not allergic to penicillin and not on antibiotic therapy Exclusion: CSF infected at time of surgery or allergic reaction to methicillin Treatment: 35; control: 39
Interventions	Methicillin IV (12.5mg/kg) every 6 hours beginning 6 hours before surgery and continuing for a total of 72 hours versus saline as placebo
Outcomes	Proportion of participants who had shunt infection. 5 of the 7 infections occurred within the first month
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomly selected by coin toss"
Allocation concealment (selection bias)	Low risk	Only the pharmacist had a record of the result of randomizations
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The drug and placebo were placed in identically marked vials
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	High risk	3 participants (4%) lost to follow‐up
Selective reporting (reporting bias)	Low risk	Study protocol well defined and pre‐specified outcome measures and analysis were available
Other bias	Low risk	The study appears to be free of other sources of bias