Kellum 1985.

Methods	RCT; 3 parallel groups. Unit of randomization: individual.
Participants	Dates of data collection: September 1982 to September 1983. Setting: University of Mississippi Medical Center. Inclusion criteria: women undergoing non‐elective CS (including prolonged ruptured membranes and prolonged labor, as well as general risk factors such as poor nutrition and poverty). Exclusion: current antibiotics, known infectious process, allergy to cephalosporins.
Interventions	Intervention: 2nd generation cephalosporin: cefamandole 2 g in 800 mL saline irrigation during the procedure; N = 84. Intervention: placebo: saline irrigation; N = 86. Comparison: no treatment: no treatment; N = 92. As the objective of this review is to compare antibiotic with no antibiotic, rather than the effect of irrigation, the 2 irrigation groups are compared.
Outcomes	Febrile morbidity (> 100.6oF twice 6 hrs apart after 1st post‐operative day); serious morbidity (fever and endomyometritis or abscess requiring IV antibiotics for resolution).
Notes	Authors' definition of high risk does not correspond to that used for non‐elective in this review, classified as 'both'. The outcome of serious morbidity included endomyometritis and is classified as endometritis in this review. Class of antibiotic: 2nd generation cephalosporin. Subgroups: type CS unclear; after cord clamping.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "Randomized by last digit of hospital admission number". Comment: quasi‐randomized trial.
Allocation concealment (selection bias)	Unclear risk	Comment: no information provided.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: no loss to follow‐up or exclusion of participants reported, but follow up given for only 77/84 of treatment and 53/86 of placebo group for outcome of serious infection, without explanation; no evidence ITT analysis was performed.
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information to judge.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: placebo‐controlled (normal saline irrigation). No further information provided.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: insufficient information to judge.
Other bias	Low risk	Comment: no other sources of bias identified.