Webster 2006.

Study characteristics
Methods	Study design: RCT Dates study conducted: February 2001‐March 2003
Participants	Number of participants: 631 eligible; 210 randomised; 206 reported Setting: Brisbane Country: Australia Population: mixed Inclusion criteria: > 18 years of age; able to give written informed consent Condition for hospitalisation: general surgery and medical patients who require IUCs as part of their health care Exclusion criteria: patients with a suprapubic catheter or a long‐term IUC who were pregnant or newly diagnosed with gynaecologic cancer Use of antibiotic prophylaxis: not reported
Interventions	Group A (n = 98): removal of IUC at 6 am Group B (n = 97): removal of IUC at 10 pm Size and type of catheter used (e.g. Foley 16F): not reported Study definition of short‐term catheterisation (days): not reported Intended duration of catheterisation for each group: A: IUC removal at 6 am B: IUC removal at 10 pm
Outcomes	Time between catheter removal and discharge (h) Duration of catheterisation (h) Time to first void (h) Mean volume of first void Recatheterisation/failed trial of void Post discharge urinary problems: retention; difficulty passing urine; pain when passing urine; loin pain; febrile; incontinent
Definition of CAUTI or bacteriuria	Not reported
Sponsorship/funding	The Queensland Nursing Council and the Queensland University of Technology funded the study.
Ethical approval	The hospital’s human research ethics committee approved the study, and the authors obtained informed consent from all participants
Notes	Sample size calculation stated The ward or location in which the catheter was inserted and fluid intake in the previous 24 h were also recorded.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Randomization was performed using a computer‐generated table of random numbers supplied by the hospital’s perinatal research centre.” Comment: adequate randomisation method
Allocation concealment (selection bias)	Low risk	Quote: “Individuals were allocated to either to 22:00‐hour catheter removal (intervention group), or to 06:00‐hour catheter removal (control group) by telephone call to a scientist who was independent of the recruitment process and blinded to baseline interview.” Comment: adequate concealment method
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: “Neither the clinicians nor the patients were blinded to the intervention.” Comment: blinding of participants and staff is not possible
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: “Ward staff, who were aware of group assignment but who were not part of the research team, recorded outcome data. Data were processed and coded by a researcher who was unconnected with treatment but who was not blind to randomization.” Comment: attempts were made to blind outcome assessment but still prone to detection bias
Blinding of microbiological outcome (detection bias)	Low risk	No microbiological outcome reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	All data reported in full. No exclusions or withdrawals
Selective reporting (reporting bias)	Low risk	All outcomes reported in full in methods and results sections
Other bias	Low risk	Appears to be free from other sources of bias