Stage 1982.

Methods	Design: randomised double‐blinded No. eligible: not stated No. randomised: unclear, but appears to be 284 (see drop‐outs/withdrawals below) No. analysed: 273 Drop‐outs/withdrawals: 11 from overall study (which included 199 caesarean section patients; data not in this review) due to incomplete records Years of recruitment: 1976 to 1978 Setting: 14 centres, United Stated
Participants	Inclusion criteria: women having vaginal or abdominal hysterectomy (women having caesarean section ineligible; data not included in this review) Exclusion criteria: preoperative infection, allergy to study drugs. Age: mean 35 to 42 years Type of hysterectomy: abdominal or vaginal
Interventions	Treatment: 1 gram cephradine (first‐generation cephalosporin) Control: placebo Route: IV Single/multiple doses: multiple Timing of doses: first dose within 1 hour of surgery, second dose 4 hours later
Outcomes	Postoperative infection, early Abdominal wound infection Urinary tract infection Adverse effects Need for therapeutic antibiotics Hospital length of stay (no SDs given)
Funding	Not stated
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	States that "each investigator was provided with an individually randomised block of patient numbers"
Allocation concealment (selection bias)	Low risk	Method not reported
Blinding (performance bias and detection bias) All outcomes	Low risk	States that "patients and investigators were blind to the allocation throughout the study"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Although proportion of withdrawals and reasons for withdrawal were not reported for each treatment group, total withdrawals constitute a small fraction of participants randomised (4%)
Selective reporting (reporting bias)	Low risk	Data available on all prespecified outcomes
Other bias	Low risk	Baseline demographic characteristics similar between treatment groups