Kobayashi 2007.

Study characteristics
Methods	Study design: Parallel‐group randomised trials Duration of trial: May 2001 to December 2004 Duration of follow‐up: 6 weeks Country of origin: Japan
Participants	Baseline characteristics Number randomised: 491 participants Number analysed: 484participants Intervention: MBP+oAB Number of participants [n]: 242 Age [years; mean (range)]: 67.9 (31‐92) Gender [male/female; n]: 154/88 Control: MBP Number of participants [n]: 242 Age [years, mean (range)]: 69.1 (46‐95) Gender [male/female; n]: 137/105 Inclusion criteria  "At least 20 years of age and referred for elective surgery for colorectal cancer" Exclusion criteria Quote: ""Contraindication to mechanical bowel preparation, known allergy to a penicillin or cephalosporin, treatment with any antibiotic within the past 2 weeks, pregnancy, and evidence of an infection at the time of surgery moderate or severe liver disease (alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, or total bilirubin more than five times the upper limit of normal), or severe renal impairment (serum creatinine >220 µmol/l)" Baseline imbalances none
Interventions	Comparison Intervention: MBP+oAB Control: MBP MBP Agent(s): polyethylene glycol Dose per administration: 2000 mL Time(s) of intake: at 10:00, completed by 14:00, on the day before surgery Route: oral Concomitant medications: ‐ oAB Agent(s): kanamycin and erythromycin Dose per administration: 1000 mg and 400 mg Time(s) of intake: at 14:00, 15:00, and 23:00 h on the day before surgery Route: oral Concomitant medications: ‐ Perioperative intravenous antibiotic prophylaxis Agent(s): cefmetazole Dose per administration: 1 g Time(s) of intake:Quote: " "after the induction of anesthesia, and an additional dose if the operation was prolonged beyond 3 h, and cefmetazole was administered again twice daily for 3 consecutive days after the operation" Adherence to regimen: ‐
Outcomes	Outcomes sought in review and reported in trial SSI (superficial and organ/space) Outcomes sought but not reported in trial Anastomotic leakage Mortality Postoperative complications (mild D/C I + II or severe D/C III+IV) Incidence of postoperative ileus Length of hospital stay Side effects of Intervention(s) Outcomes reported in trial but not used in review SSI according to the surgical procedure (colon vs. rectum)
Notes	Source of funding: ‐ Conflicts of interest: ‐ Ethics approval: "The study was approved by the ethics boards of the participating centers." Informed consent: "Written informed consent was required" Clinical trials registration: ‐ Sample size calculation: "On the basis of an SSI rate of 11% at the last evaluable follow‐up assessment for both treatment groups, a power of 0.80, and the requirement to show that intravenous antimicrobial prophylaxis was noninferior to oral and intravenous antimicrobial prophylaxis with a δ of 8%, a total sample size of 482 patients (241 assigned to intravenous anti microbial prophylaxis, and 241 assigned to oral and intravenous antimicrobial prophylaxis) satisfying the criteria for the intention‐to‐treat population was calculated to be required. Taking into account an estimated ineligibility rate before the start of the study of 5%, a total of about 500 patients was thus considered to be needed."