Viitanen 1984 A.

Methods	Clinical controlled trial. Allocation by birthday. Patient blinded. Unclear blinding of surgeon and outcome assessor.
Participants	588 eligible patients. 123 excluded after randomisation. 465 enrolled in the study. Age‐range: 15‐94 Mean: 33,4 315 enrolled in this part of the study. The study has 3 subgroups (see Viitanen 1984 B). In Viitanen 1984 A 315 patients enrolled in study.
Interventions	Treatment group: Tinidazole 500 mg in 100 saline i.v preoperatively. Placebo group: No treatment.
Outcomes	Wound infection (Pus from the wounds). Two patients died, 1 of peritonitis induced by perforation of the appendix, 1 died of cardiac infarction.
Notes	Treatment initiated on anaesthetized patient. No drain treatment.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	High risk	C ‐ Inadequate