Duffy 1995

Methods	DESIGN: Randomised controlled trial ALLOCATION: Not described but did stratify participants according to presence/ absence of UTI and trial site. BLINDING PROCEDURES: Unclear SAMPLE CALCULATION: Yes post hoc DURATION: 3 months FOLLOW‐UP: days 2, 4, 6, 10, 15, 60 & 90 WITHDRAWALS/DROPOUTS: 2 ITT: Not stated GEOGRAPHICAL LOCATION: USA SETTING: 3 long‐term care Veterans Administration Medical Centre Nursing Homes
Participants	N = 80 DIAGNOSIS: Incomplete bladder emptying due to prostate obstruction ELIGIBLE: 203 ENROLLED: 82 COMPLETED: 80 to day 15; 39 completed to Day 90) AGE: Elderly GENDER: Male
Interventions	Sterile technique vs clean technique (also single vs multiple use): sterile equipment and procedure, cleaning with betadine; Clean technique: catheter washed with soap and water and reused x 1 week (uncoated, non‐lubricated catheters)
Outcomes	Number of treatment episodes for UTI + urinalysis.
Notes	Some participants had indwelling catheters prior to enrolment in the trial (not stated how many); weeks to onset of symptomatic UTI was 3.11 (3.12) for treatment and 3.5 (3.02) for control. Dropout rate high after Day 15 with only 39 completing data collection to Day 90.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomly assigned"
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	Low risk	No blinding, but the review authors judge that the outcome and outcome measurement are not likely to be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No blinding of outcome assessment ‐ this may have resulted in bias
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	All participants had full dataset for Day 15, but missing outcome data at end of 90 days
Source of Funding	Low risk	Dept of Veterans Affairs US.