Approximately 90,000 people in the United Kingdom have a long-term catheter. Use of long-term catheters is associated with common adverse events including blockage of the catheter and symptomatic catheter-associated urinary tract infection. Washout solutions are often used prophylactically to prevent these adverse events, but evidence for the benefits and potential harms is insufficient.
Does the addition of weekly prophylactic washouts of the catheter to standard long-term catheter care improve the outcomes of adults with long-term catheter.
A pragmatic three-arm multicentre open-label superiority randomised controlled trial with embedded qualitative study.
Adults with long-term catheter in situ (any route or type) with no plans to discontinue long-term catheter use were recruited in a community setting in the United Kingdom. Participants received training to self-administer the washouts, with/without the assistance of a carer.
Participants were randomised 1 : 1 : 1 to standard long-term catheter care plus weekly prophylactic saline washouts; weekly prophylactic acidic washouts; or no prophylactic washouts.
The primary clinical and health economic outcomes were catheter blockage requiring intervention (/1000 catheter days) up to 24 months post randomisation and incremental cost per quality-adjusted life-year gained. Outcome data were patient reported.
Eighty of the planned 600 participants were recruited (26 saline; 27 acidic; 27 control). There was a reduction in incidence of blockages requiring treatment (per 1000 catheter days) from 20.92 (control) to 9.96 (saline) and 10.53 (acidic). The incidence rate ratio favoured the washout groups [saline 0.65 (97.5% confidence interval 0.24 to 1.77); p = 0.33 and acidic 0.59 (97.5% confidence interval 0.22 to 1.63); p = 0.25] but was not statistically significant. There was a reduction in the secondary outcome of symptomatic catheter-associated urinary tract infection requiring antibiotic use (per 1000 catheter days) from 8.05 (control) to 3.71 (saline) and 6.72 (acidic). The incidence rate ratio favoured the washout groups [saline 0.40 (97.5% confidence interval 0.20 to 0.80); p = 0.003 and acidic 0.98 (97.5% confidence interval 0.54 to 1.78); p = 0.93]; however, the significance should be interpreted cautiously given the small sample size. There were few adverse events. Quality-of-life outcomes were similar between groups. Due to the low sample size, the health economic outcomes could not be analysed. The embedded qualitative work demonstrated that the study design was feasible and acceptable to healthcare professionals and participants involved with the trial. Healthcare professionals perceived the training of participants to have minimal impact on healthcare resources and participants were empowered to self-manage the washouts and integrate it into their routine care.
COVID-19 led to recruitment difficulties and early termination of the study by the funder. Sample size was not met.
There is a suggestion that regular prophylactic washout use may result in the reduction of catheter blockage and symptomatic catheter-associated urinary tract infection. However, the results are inconclusive due to the small sample size. Participants found the washouts acceptable to use and could self-manage the washouts with training.
The study design was acceptable to involved participants and healthcare workers. We recommend a multinational randomised controlled trial to produce evidence on the clinical effectiveness of long-term catheter washout policies.
This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number 17/30/02.
Long-term catheters are used by approximately 90,000 people in the United Kingdom for various reasons. Common problems when using the long-term catheter are blockages of the catheter and urine infections which often require healthcare assistance and impact on quality of life. To help prevent these problems, current standard care involves changing the catheter every 12 weeks or so. Some people also flush the catheter regularly with washout solutions, but there is no good evidence to support this. The CATHETER II study evaluated if flushing the catheter regularly reduces the number of blockages, urine infections and other catheter problems. It also asked participants if the washouts were acceptable to use and improved their quality of life. We recruited adults with long-term catheter in the United Kingdom to take part. They were randomly allocated to (1) preventative washouts with saline, or (2) preventative washouts with citric acid, or (3) no preventative washouts. All participants continued standard long-term catheter care. Participants, or their carer, were trained to do the washouts and these were administered every week for up to 24 months. We contacted participants by telephone every month to ask about any problems with the catheter or washouts and asked them to complete a questionnaire about their quality of life every 6 months. We interviewed participants and healthcare professionals to better understand their experience in the study. The study ended early because it was difficult to recruit participants during the COVID-19 pandemic, with 80 of the planned 600 participants recruited. Therefore, the results are not conclusive but do suggest that regular preventative washouts might reduce the number of blockages of the catheter and urine infections. Participants and healthcare professionals who were interviewed said that people with long-term catheter can be trained to do the washouts effectively. Participants had a generally positive experience using the washouts. Further studies will be needed.
Health technology assessment (Winchester, England). 2026 Mar [Epub]
Diana Johnson, Sheela Tripathee, David Cooper, Lynda Constable, Muhammad Imran Omar, Sara MacLennan, Seonaidh Cotton, Konstantinos Dimitropoulos, Suzanne Evans, Hashim Hashim, Mary Kilonzo, James Larcombe, Paul Little, Graeme MacLennan, Peter Murchie, Phyo Kyaw Myint, James N'Dow, John Norrie, Catherine Paterson, Karen Powell, Graham Scotland, Nikesh Thiruchelvam, Amanda Young, Mohamed Abdel-Fattah
Centre for Healthcare Randomised Trials, Health Services Research Unit, University of Aberdeen, Aberdeen, UK., Academic Urology Unit, University of Aberdeen, Aberdeen, UK., Department of Urology, Aberdeen Royal Infirmary, NHS Grampian, Foresterhill Health Campus, Aberdeen, UK., Bladder Health UK, Birmingham, UK., Bristol Urological Institute, Southmead Hospital, North Bristol NHS Trust and University of Bristol, Bristol, UK., Health Economics Research Unit, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK., Locum GP, Sedgefield, UK., Primary Care Research Centre, University of Southampton, Southampton, UK., Academic Primary Care Research Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK., Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK., Centre for Public Health, Queens University Belfast, Institute of Clinical Sciences, Royal Victoria Hospital Belfast, Belfast, UK., School of Nursing, Midwifery and Public Health, University of Canberra, Bruce, ACT, Australia., Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK., The Queen's Nursing Institute, London, UK., Aberdeen Centre for Women's Health Research, University of Aberdeen and Institute for Applied Health Sciences, Aberdeen Maternity Hospital, Aberdeen, UK.