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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
People who perform clean intermittent self-catheterisation can reduce symptomatic urinary tract infections from two per year to one by taking daily low-dose antibiotics.
This NIHR-funded trial randomised 404 adults in the UK who perform the procedure for a variety of reasons to either daily oral low-dose antibiotics or no prophylaxis. All had a recent history of urinary tract infection.
Although prophylactic antibiotics halved infection rates, it increased antimicrobial resistance compared with the control group who took short courses of antibiotics for each infection. This has implications for the individual and wider population. As overall reported health status was similar between the two groups, it is unclear if this reduction in infection is sufficient to justify wider use of prophylactic antibiotics.
Why was this study needed?
People with bladder obstruction or who have problems with muscle contraction due to neurological disorders may be unable to empty their bladders normally.
Inserting catheters to drain their bladder 3 to 5 times a day is one option. The number of people performing self-catheterisation in the UK is unknown, but approximately 66 million catheters for self-use were prescribed in 2015, costing £103 million.
Up to 88% of people who carry out self-catheterisation experience repeated urinary tract infections (UTIs). The evidence base for daily use of low-dose antibiotics to prevent UTIs in this group of people is currently lacking.
What did this study do?
The AnTIC open-label trial randomised 404 adults from 51 NHS sites to receive either low dose daily antibiotics or no prophylaxis. All participants undertook self-catheterisation and were expected to continue doing so for at least 12 months, and had a previous history of UTIs associated with self-catheterisation. Participants had long-term underlying conditions such as multiple sclerosis, spina bifida or spinal injury.
The prophylaxis group received nitrofurantoin, trimethoprim or cephalexin according to individual suitability. Switching was possible if telephone assessments throughout the study indicated a clinical need.
Study assessors were blinded to treatment allocation, but participants and clinicians were not which may have affected the threshold that each group used for reporting or seeking treatment for UTIs.
What did it find?
- People who took daily low-dose antibiotics had one UTI over 12 months (interquartile range [IQR] 0 to 2) on average compared with two UTIs in the no prophylaxis group (IQR 1 to 4).
- Low-dose antibiotics reduced the risk of symptomatic UTI by 48% (incidence rate ratio [IRR] 0.52, 95% confidence interval [CI] 0.44 to 0.6). For microbiologically confirmed UTIs, the result was similar (IRR 0.49, 95% CI 0.39 to 0.60).
- An increase in resistance to most of the antibiotics used was found in the prophylaxis group from asymptomatic samples taken from three months onwards, but there was no evidence of an increase in resistance in the control group. By 9 to 12 months, resistance to nitrofurantoin, trimethoprim and co-trimoxazole had significantly increased in the prophylaxis group.
- Health status did not differ between the groups at 12 months according to the Short Form questionnaire-36, in terms of their physical component summary score or mental component summary score.
- The added cost of preventing one UTI was £99. This did not factor in costs associated with increased antibiotic resistance.
What does current guidance say on this issue?
NICE 2017 guidelines focus on the question of antibiotic prophylaxis for long-term indwelling urinary catheters and in this situation recommend that prophylactic antibiotics should not be routinely given. However, they may be considered for people who have either a history of symptomatic UTIs after catheter change, or who experience trauma during catheter changes.
Current NICE guidelines make no recommendation on the use of antibiotic prophylaxis in intermittent self-catheterisation.
What are the implications?
For people carrying out self-catheterisation, recurrent UTIs add to the difficulties they face with their pre-existing conditions. Though this trial found that low-dose prophylactic antibiotics reduces the risk of UTI, and maybe a useful reduction for some people, it comes at a personal inconvenience of increased pill burden. This potential benefit must be balanced against the potential harm of antimicrobial resistance.
Interestingly, the rate of infection in both groups was much lower than the average of five infections in the year before the study commenced. It may be that the study conditions, such as increased clinical contact or improved technique, reduced the infection risk.
Citation and Funding
Pickard R, Chadwick T, Oluboyede Y, et al. Continuous low-dose antibiotic prophylaxis to prevent urinary tract infection in adults who perform clean intermittent self-catheterisation: the AnTIC RCT. Health Technol Assess. 2018;22(24):1-102.
This project was funded by the National Institute for Health Research Health Technology Assessment programme (project number 11/72/01).
Bibliography
NICE. Healthcare-associated infections: prevention and control in primary and community care. CG139. London: National Institute for Health and Care Excellence; 2017.
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