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.

Abstract

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); 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.

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.