Comparing the clinical and cost-effectiveness of various washout policies in preventing catheter associated complications in adults living with long-term catheters: synopsis of the CATHETER II RCT.

Background: 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. Objectives: 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. Design and methods: A pragmatic three-arm multicentre open-label superiority randomised controlled trial with embedded qualitative study. Setting and participants: 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. Interventions: 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. Main outcome measures: 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. Results: 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); Limitations: COVID-19 led to recruitment difficulties and early termination of the study by the funder. Sample size was not met. Conclusions: 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. Future work: 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. Funding: 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.