Darouiche 2005.

Methods	Study design: parallel, placebo‐controlled, double‐blind RCT (3:1) Study duration: not reported Duration of follow‐up: 1 year
Participants	Country: USA Setting: single institution, outpatient Adults with spinal cord injuries for ≥ 1 year, neuropathic bladders requiring catheterization (indwelling or intermittent catheters), ≥ to 2 symptomatic UTI in preceding year Number: treatment group (21); control group (6) Mean age, range (years): treatment group (52, 27 to 71); control group (52, 28 to 74) Sex: all males Comorbidities: not reported Exclusion criteria: supravesical urinary diversion; VUR; obstructing urolithiasis; indwelling nephrostomy catheter; extra urogenital infections requiring prolonged antibiotics; uncontrolled DM; immunosuppression; children
Interventions	Treatment group Intravesical instillation: 30 mL of E. coli 83972 suspension (106 CFU/mL of saline) for 2 hours, then drained. Twice/d for 3 consecutive days Control group Intravesical instillation: 30 mL of sterile saline for 2 hours, then drained. Twice/d for 3 consecutive days
Outcomes	Symptomatic UTI: significant bacteriuria (≥ 105 CFU/mL) and pyuria (> 10 WBC/HPF) plus one or more of the following signs or symptoms for which no other aetiology could be identified: Fever, suprapubic or flank discomfort, bladder spasm, increased spasticity and worsening dysreflexia
Notes	Only males were enrolled with no female enrolment Results are confusing, initially mentioned that 62% of patients in treatment group compared to 100% of patients in control group developed at least 1 episode of UTI during the 1‐year follow‐up (P = 0.7). However, when survival analysis via Kaplan‐Meier curves were done, the patients who were unsuccessfully colonised in the treatment group were considered part of placebo group for statistical comparison. When groups were adjusted, study reported 46% in treatment group versus 93% in placebo group develop at least 1 episode of UTI during the 1‐year follow‐up with Kaplan‐Meier curves showing better survival for those successfully colonised (P = 0.002) Funding source: Rehabilitation Research and Development Service grant from Department of Veterans Affairs, Paralysed Veterans of America Spinal Cord Research Foundation, US Public Health Service
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Study was described as randomised, method of randomisation was not reported
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Stated that patients were blinded. It was stated that nurse administering the bladder instillation was not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Stated clearly that evaluator was blinded to randomisation group
Incomplete outcome data (attrition bias) All outcomes	High risk	All patients accounted for up to 1 year follow‐up. For patients randomised into the treatment group, if they failed inoculation, they were then combined with the patients in the placebo group for statistical comparisons. High risk of bias as it not fully intention to treat
Selective reporting (reporting bias)	High risk	Only adverse event reported was one participant had autonomic dysreflexia. Generally stated that there was lack of evidence of septicaemia and UTI attributable to E. coli 83972
Other bias	Low risk	Study appears free of other biases