Andersen 1980.

Methods	Study: prospective, randomised. Allocation: NM. Blinding: yes.
Participants	287 patients: 137 P / 150 C
Interventions	Herniorrhaphy ATB: ampicillin 1 gr subfascial. MA: before closure fascial. Control: no treatment
Outcomes	IP= 5; IC= 6
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "A triple‐blind, random‐allocation design was used." Comment: Information not provided about sequence generation.
Allocation concealment (selection bias)	Unclear risk	Quote: "...were assigned at the end of the operation to one of the following four regimens:..." Comment: Probably not done.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not mentioned.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not mentioned.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned.