Continuous low-dose antibiotic prophylaxis to prevent urinary tract infection in adults who perform clean intermittent self-catheterisation: the AnTIC RCT
Authors: Pickard Robert , Chadwick Thomas , Oluboyede Yemi , Brennand Catherine , von Wilamowitz-Moellendorff Alexander , McClurg Doreen , Wilkinson Jennifer , Ternent Laura , Fisher Holly , Walton Katherine , McColl Elaine , Vale Luke , Wood Ruth , Abdel-Fattah Mohamed , Hilton Paul , Fader Mandy , Harrison Simon , Larcombe James , Little Paul , Timoney Anthony , N’Dow James , Armstrong Heather , Morris Nicola , Walker Kerry , Thiruchelvam Nikesh 
Published: May 2018

BackgroundPeople carrying out clean intermittent self-catheterisation (CISC) to empty their bladder often suffer repeated urinary tract infections (UTIs). Continuous once-daily, low-dose antibiotic treatment (antibiotic prophylaxis) is commonly advised but knowledge of its effectiveness is lacking.ObjectiveTo assess the benefit, harms and cost-effectiveness of antibiotic prophylaxis to prevent UTIs in people who perform CISC.DesignParallel-group, open-label, patient-randomised 12-month trial of allocated intervention with 3-monthly follow-up. Outcome assessors were blind to allocation.SettingUK NHS, with recruitment of patients from 51 sites.ParticipantsFour hundred and four adults performing CISC and predicted to continue for ≥ 12 months who had suffered at least two UTIs in the previous year or had been hospitalised for a UTI in the previous year.InterventionsA central randomisation system using random block allocation set by an independent statistician allocated participants to the experimental group [once-daily oral antibiotic prophylaxis using either 50 mg of nitrofurantoin, 100 mg of trimethoprim (Kent Pharmaceuticals, Ashford, UK) or 250 mg of cefalexin (Sandoz Ltd, Holzkirchen, Germany);n = 203] or the control group of no prophylaxis (n = 201), both for 12 months.Main outcome measuresThe primary clinical outcome was relative frequency of symptomatic, antibiotic-treated UTI. Cost-effectiveness was assessed by cost per UTI avoided. The secondary measures were microbiologically proven UTI, antimicrobial resistance, health status and participants’ attitudes to antibiotic use.ResultsThe frequency of symptomatic antibiotic-treated UTI was reduced by 48% using prophylaxis [incidence rate ratio (IRR) 0.52, 95% confidence interval (CI) 0.44 to 0.61;n = 361]. Reduction in microbiologically proven UTI was similar (IRR 0.49, 95% CI 0.39 to 0.60;n = 361). Absolute reduction in UTI episodes over 12 months was from a median (interquartile range) of 2 (1–4) in the no-prophylaxis group (n = 180) to 1 (0–2) in the prophylaxis group (n = 181). The results were unchanged by adjustment for days at risk of UTI and the presence of factors giving higher risk of UTI. Development of antimicrobial resistance was seen more frequently in pathogens isolated from urine andEscherichia colifrom perianal swabs in participants allocated to antibiotic prophylaxis. The use of prophylaxis incurred an extra cost of £99 to prevent one UTI (not including costs related to increased antimicrobial resistance). The emotional and practical burden of CISC and UTI influenced well-being, but health status measured over 12 months was similar between groups and did not deteriorate significantly during UTI. Participants were generally unconcerned about using antibiotics, including the possible development of antimicrobial resistance.LimitationsLack of blinding may have led participants in each group to use different thresholds to trigger reporting and treatment-seeking for UTI.ConclusionsThe results of this large randomised trial, conducted in accordance with best practice, demonstrate clear benefit for antibiotic prophylaxis in terms of reducing the frequency of UTI for people carrying out CISC. Antibiotic prophylaxis use appears safe for individuals over 12 months, but the emergence of resistant urinary pathogens may prejudice longer-term management of recurrent UTI and is a public health concern. Future work includes longer-term studies of antimicrobial resistance and studies of non-antibiotic preventative strategies.Trial registrationCurrent Controlled Trials ISRCTN67145101 and EudraCT 2013-002556-32.FundingThis project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full inHealth Technology AssessmentVol. 22, No. 24. See the NIHR Journals Library website for further project information.