El‐Mazny 2014.

Study characteristics
Methods	Study design: RCT Dates study conducted: November 2012‐March 2014
Participants	Number of participants: 335 eligible; 300 randomised; 300 reported Setting: Cairo Country: Egypt Population: women Age (mean and SD): Group A: 24.5 ± 4.2; Group B: 23.8 ± 3.9 Inclusion criteria: women admitted to the prenatal wards for primary or repeat elective CS were screened to determine eligibility for inclusion. Condition for hospitalisation: primary or elective CS Exclusion criteria: urinary infection (assessed clinically and by midstream urinalysis); significant vaginal bleeding; severe pre‐eclampsia or eclampsia; and/or any other conditions requiring post‐operative monitoring of urinary output; contraindications for general anaesthesia Use of antibiotic prophylaxis: cefazolin 2 g IV single dose 30 min before surgery
Interventions	Group A (n = 150): IUC removed immediately after the procedure Group B (n = 150): IUC removed 12 h post‐operatively Size and type of catheter used: 16F Study definition of short‐term catheterisation (days): not reported Intended duration of catheterisation for each group: Group A: IUC removed immediately post‐op Group B: IUC removed 12 h post‐op
Outcomes	Significant bacteriuria Urinary retention Dysuria Urinary frequency Urgency Time to post‐op ambulation (h) Time to first void post‐op (h) Hospital stay (h)
Definition of CAUTI or bacteriuria	Significant bacteriuria = > 105 bacteria per mL urine in a midstream sample collected 24 h post‐operatively
Sponsorship/funding	Not reported
Ethical approval	The study protocol was approved by the Scientific Research Committee, and informed consent was obtained from all participants.
Notes	If patient still had difficulty in passing urine after 6 h and/or if abdominal examination showed palpable urinary bladder, recatheterisation was done
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “A total of 300 women were allocated into two groups in a 1:1 ratio by block randomisation using computer‐generated random numbers.” Comment: adequate method of randomisation
Allocation concealment (selection bias)	High risk	Not reported. Unlikely that allocation concealment was performed
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not reported. Unlikely blinding was possible
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Blinding of microbiological outcome (detection bias)	Low risk	Not reported. It is likely that urine samples were sent to a laboratory where the microbiologist would be unlikely to know if patients were in a trial or not
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals reported
Selective reporting (reporting bias)	Low risk	All outcomes are reported in both the methods and results section and are fully accounted for
Other bias	Low risk	Nothing to indicate any other source of bias