Hares 1981.

Methods	Study design: randomized control study Study dates: not reported Setting: 1 centre Country: UK
Participants	Inclusion criteria: all participants entering hospital for cystoscopy over the trial period Exclusion criteria: indwelling catheter left in situ following cystoscopy, urine infection on admission Sample size: 122 cystoscopies were performed on 112 participants, 10 cases were excluded from analysis, 112 cystoscopies included for analysis Age (years): median: control group: 66; treatment group: 64 Sex: 79 men and 33 women
Interventions	Group 1 (n = 56): bladder irrigation with no antibiotic solution added Group 2 (n = 56): bladder irrigation with 6 vials of Polybactrin Soluble GU containing polymyxin B sulphate 450,000 units, neomycin sulphate 120,000 units, and bacitracin 6000 units to each bag of irrigating fluid
Outcomes	Symptomatic UTI How measured: urine samples with a count of micro‐organisms > 105 CFU/mL, or confluent or semi‐confluent growth of micro‐organisms on the dip slides, together with symptoms of cystitis and a sterile pyuria on a subsequent midstream specimen of urine Time points measured: on morning after the cystoscopy, a mid‐stream sample of urine was taken. After discharge, the participant was asked to provide dip slides on the 3rd, 7th and 14th day after cystoscopy. These were sent to the laboratory by first class post Time points reported: not reported Outcomes: control group: 5/56 participants had symptomatic UTI after cystoscopy; treatment group: 1/56 had symptomatic UTI after cystoscopy Asymptomatic bacteriuria How measured: urine samples with a count of micro‐organisms > 105 CFU/mL, or confluent or semi‐confluent growth of organisms on the dip slides, but without any symptoms Time points measured: midstream urine samples 5 days after cystoscopy Time points reported: not reported Outcomes: control group: 4/56 participants had asymptomatic bacteriuria after cystoscopy; treatment group: 2/56 had asymptomatic bacteriuria UTI after cystoscopy
Funding sources	No information about funding
Declarations of interest	No information about conflict and interest
Notes	No email address available for contacting the corresponding author for further information
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The patients were randomly allocated to either the control group or the treatment group by the theatre sister." Comment: method for generation of random sequence not given.
Allocation concealment (selection bias)	Unclear risk	Comment: no information regarding the concealment of randomization.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "The composition of fluid was only known by the pharmacists, participants were randomly allocated to either the control or the treatment group." Comment: participants and personnel blinded to intervention.
Blinding of outcome assessment (detection bias) Subjective outcomes	Low risk	Quote: "The composition of fluid was only known by the pharmacists, participants were randomly allocated to either the control or the treatment group." Comment: blinding of participants and personnel performed adequately.
Blinding of outcome assessment (detection bias) Objective outcomes	Unclear risk	Comment: not applicable, since the objective outcome of drug resistance was not reported.
Incomplete outcome data (attrition bias) Systemic UTI	Unclear risk	Comment: outcome not reported.
Incomplete outcome data (attrition bias) Symptomatic UTI	Low risk	Quote: "122 cystoscopies were randomized, six of the cystoscopy results were removed from the trial because the participants failed to return sufficient dip slides or urine specimens, 4 cases where the urine was infected on admission were also excluded but their follow up results were reported, 112 cases (56 participants in each group) were analyzed." Comment: overall, loss to follow‐up was less and their reasons given; therefore, judged adequate.
Incomplete outcome data (attrition bias) Serious adverse events	Unclear risk	Comment: outcome not reported.
Incomplete outcome data (attrition bias) Minor adverse events	Unclear risk	Comment: outcome not reported.
Incomplete outcome data (attrition bias) Localized UTI	Unclear risk	Comment: outcome not reported.
Incomplete outcome data (attrition bias) Asymptomatic bacteriuria	Low risk	. Quote: "122 cystoscopies were randomized, six of the cystoscopy results were removed from the trial because the participants failed to return sufficient dip slides or urine specimens, 4 cases where the urine was infected on admission were also excluded but their follow up results were reported, 112 cases (56 participants in each group) were analyzed." Comment: overall, loss to follow‐up was less and their reasons given; therefore, judged adequate.
Incomplete outcome data (attrition bias) Bacterial resistance	Unclear risk	Comment: outcome not reported.
Selective reporting (reporting bias)	Unclear risk	Comment: data reported on all outcomes specified in methods section, but there was no access to trial protocol/registration to further assess selective reporting.
Other bias	Low risk	Comment: no other bias detected.