Mathews 1979.

Methods	Design: randomised double‐blinded No. eligible: not stated No. randomised: not explicitly stated No. analysed: 50 Drop‐outs/withdrawals: none reported Years of recruitment: 1975 to 1978 Setting: All Saints' Hospital, Chatham, UK
Participants	Inclusion criteria: women given appointments to be admitted for vaginal hysterectomy Exclusion criteria: prophylactic antibiotics considered essential or contraindicated, allergy to study drugs Age: mean 56 to 61 years Type of hysterectomy: vaginal
Interventions	Treatment: 10 mL co‐trimoxazole (sulphonamide), containing total of 800 mg sulphamethoxazole and 160 mg trimethoprim Control: placebo Route: IV Single/multiple doses: single Timing of dose: at beginning of operation
Outcomes	Urinary tract infection Pelvic infection Postoperative fever Need for therapeutic antibiotics Adverse effects (narrative data only) Follow‐up: 6 weeks (but only early data included in this review, as unclear whether early/late data overlap)
Funding	One study author affiliated with Wellcome Foundation
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Stated as randomised; no additional details
Allocation concealment (selection bias)	Low risk	States that conduct of study was as described in Mathews 1977 (see above)
Blinding (performance bias and detection bias) All outcomes	Unclear risk	States that conduct of study was as described in Mathews 1977 (see above)
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Proportions of withdrawals and reasons for withdrawal not reported across treatment groups
Selective reporting (reporting bias)	Low risk	Data available on all prespecified outcomes
Other bias	Low risk	Baseline demographic characteristics similar between treatment groups