Salo 1981.

Methods	Randomised controlled trial. Randomisation method not stated. Double‐blinded. Unclear blinding of outcome assessor.
Participants	223 eligible patients. 2 patients excluded after randomisation. 221 enrolled in the study. Mean: Treatment group: 32,6, Placebo group: 32,7
Interventions	Treatment group: Tinidazole 500 mg in 100 ml saline i.v preoperatively. Placebo group: Saline 100 ml properatively.
Outcomes	Wound infection (Presence of pus in the operation wound requiring surgical incision)
Notes	No comment on drain treatment.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear