Celdran 2004.

Methods	Study: prospective, randomised. Allocaton: number list. Blinding: yes
Participants	99 patients: 50 P / 49 C.
Interventions	Hernioplasty ATB: cephazolin 1 gr. MA: 30 minutes before the incision. Control: placebo
Outcomes	IP= 0; IC= 4
Notes	The interim analysis, performed after the first 91 patients had been included, recommended ending the study due to ethical reasons.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "A list of random numbers was generated to assign the treatment."
Allocation concealment (selection bias)	High risk	Quote: "A prospective, double‐blind trial was performed ..." Comment: Probably not done.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not mentioned. Comment: Probably not done.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not mentioned. Comment: Probably not done.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "All patients were examined 1 week, 1, 3, and 6 months, and 1 and 2 years postoperatively by trained impartial surgeon."