Effect of point-of-care susceptibility testing in general practice on appropriate prescription of antibiotics for patients with uncomplicated urinary tract infection: a diagnostic randomised controlled trial

OBJECTIVES: To investigate the effect of adding point-of-care (POC) susceptibility testing to POC culture on appropriate use of antibiotics as well as clinical and microbiological cure for patients with suspected uncomplicated urinary tract infection (UTI) in general practice. DESIGN: Open, individually randomised controlled trial. SETTING: General practice. PARTICIPANTS: Women with suspected uncomplicated UTI, including elderly patients above 65, patients with recurrent UTI and patients with diabetes. The sample size calculation predicted 600 patients were needed. INTERVENTIONS: Flexicult SSI-Urinary Kit was used for POC culture and susceptibility testing and ID Flexicult was used for POC culture only. MAIN OUTCOME MEASURES: Primary outcome: appropriate antibiotic prescribing on the day after consultation defined as either (1) patient with UTI: to prescribe a first-line antibiotic to which the infecting pathogen was susceptible or a second line if a first line could not be used or (2) patient without UTI: not to prescribe an antibiotic. UTI was defined by typical symptoms and significant growth in a reference urine culture performed at one of two external laboratories. Secondary outcomes: clinical cure on day five according to a 7-day symptom diary and microbiological cure on day 14. Logistic regression models taking into account clustering within practices were used for analysis. RESULTS: 20 general practices recruited 191 patients for culture and susceptibility testing and 172 for culture only. 63% of the patients had UTI and 12% of these were resistant to the most commonly used antibiotic, pivmecillinam. Patients randomised to culture only received significantly more appropriate treatment (OR: 1.44 (95% CI 1.03 to 1.99), p=0.03). There was no significant difference in clinical or microbiological cure. CONCLUSIONS: Adding POC susceptibility testing to POC culture did not improve antibiotic prescribing for patients with suspected uncomplicated UTI in general practice. Susceptibility testing should be reserved for patients at high risk of resistance and complications. TRIAL REGISTRATION NUMBER: NCT02323087; Results.