Hawrylyshyn 1983.

Methods	RCT; 3 parallel groups. Unit of randomization: individual.
Participants	Dates of data collection: July 1980 to June 1981. Setting: Mount Sinai Hospital, Toronto, Canada. Inclusion criteria: women undergoing CS (at 'high' risk because of ruptured membranes in active labor); classified as 'non‐elective'. N = 182. Exclusion criteria: febrile, antibiotic use in prior 24 hrs; allergy to penicillin or cephalosporin; significant hepatic or renal disease. Predominantly private, middle‐class and in their late 20s.
Interventions	Intervention: cephalosporin (B2a): cefoxitin 2 g IV at time of cord clamping; N = 64. Intervention: cephalosporin (B2a): cefoxitin 2 g at time of cord clamping and at 4 and 8 hrs post‐operatively; N = 60. Comparison: placebo: identical‐appearing placebo; N = 58. Both treatment groups combined in this analysis.
Outcomes	Febrile morbidity (> 38oC twice at least 8 hrs apart, after 1st post‐operative day); endometritis (fever, foul, excessive lochia or uterine tenderness); UTI (fever and positive culture); wound infection (fever, cellulitis or exudate with positive cultures).
Notes	No adverse drug reactions in cefoxitin groups, no septicemia in any group; 4 patients in placebo group were considered seriously ill (although do not fit the criteria for serious morbidity in this review) compared to none in treatment groups. Antibiotic class: cefamycin (2nd generation cephalosporin). Subgroups: non‐elective CS; after cord clamping. The 3 groups were comparable regarding age, parity, gestational age, duration of labor, duration of ruptured membranes, number of vaginal examinations, use of internal fetal monitoring or post‐operative hemoglobin.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "...randomized". Comment: no description of sequence generation process.
Allocation concealment (selection bias)	Unclear risk	Quote: "...randomly packaged in identical vials coded from 1 to 200". Comment: insufficient information provided to judge.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: no loss of participants to follow‐up; 7 patients were excluded after having entered the study. 1 patient was excluded because of an error in mixing and administering the IV injections; 6 patients were excluded because they became febrile within 8 hrs of operation and required immediate antibiotic therapy. As‐treated analysis; data from excluded patients could not be re‐included in the analysis.
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information to judge.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "...double‐blinded, placebo‐controlled" ... "The medication and an identical appearing placebo were prepared prior to the study and ... packaged in identical vials....The attending physician was unaware of what regimen his patient received and the code numbers were revealed only after the study was completed".
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "The attending physician was unaware of what regimen his patient received". Comment: probably outcome assessment was blinded.
Other bias	Low risk	Comment: no other sources of bias identified.