Kizilcan 1992 C.

Methods	Randomised controlled trial. Randomisation method not stated. Patient blinded. Unclear blinding of surgeon and outcome assessor.
Participants	100, 66 males and 34 females enrolled in the study. Age‐range: 0‐15. Patients presenting parameters suggesting complicated appendicitis were not included. The study has 4 subgroups (see Kizilcan 1992 A & B). In Kizilcan 1992 A 50 patients enrolled in the study. 6 patients excluded after randomisation.
Interventions	Treatment group: Piperacillin Na 200 mg/kg/day divided in 3 doses initiated preoperatively. Placebo group: Not specified in same regime as above
Outcomes	Wound infection (Not defined). Postoperative intraabdominal abscess (Not defined).
Notes	No drain treatment. Wrote to author to specify subgrouping on drop‐outs.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear