BERKELEY, CA (UroToday.com) - Urinary tract infection (UTI) is one of the most common infectious diseases with high costs and significant impact on patients’ quality of life. Despite the significant impact of UTIs on clinical practice, and also high indirect costs due to working days lost, the recurrence risk prediction of UTI episodes currently lacks dedicated and validated tools. There is no evidence that the clinical and laboratory parameters currently used in everyday urological clinical practice can predict the risk of recurrence. We therefore aimed to develop and externally validate a novel tool for predicting recurrence risk probability at 12 months after a urinary tract infection episode.
In this study, we included 1 141 women affected by UTIs from two different tertiary hospitals. A cohort of 373 women from one of the hospitals was used to externally validate and calibrate the nomogram. Univariate and multivariate Cox regression models tested the relationship between UTI recurrence risk and patient clinical and laboratory characteristics. The nomogram, named LUTIRE (Lower Urinary Tract Infection REcurrence risk), was evaluated by calculating concordance probabilities as well as testing calibration of predicted UTI recurrence with observed UTIs. Nomogram variables included: number of partners, bowel function, type of pathogens isolated (Gram positive/negative), hormonal status, number of previous UTI recurrences, and previous treatment of asymptomatic bacteriuria. Two hundred and sixty-one out of 768 women in the other hospital presented at least one recurrence episode of UTI (33.9%). Our nomogram had a concordance index of 0.85 and showed high discrimination accuracy and favorable calibration characteristics. In the validation group (373 women) the overall c-index was 0.83 (p=0.003, 95% CI 0.51–0.99), while the area under the ROC curve was 0.85 (95% CI 0.79-0.91).
In our study, for the first time, we developed and validated an easy nomogram based on several parameters -- both from the patients and the bacteria -- for predicting the recurrence risk of UTI. Our LUTIRE nomogram, in fact, is able to predict with good accuracy the probability of a new UTI episode in women. Moreover, it is able to select patients at high risk of symptomatic recurrence to plan appropriate preventive strategies. This aspect is extremely important in the era of antibiotic resistance crisis, due to the fact that only selected patients should be offered prophylactic measures such as antibiotic drugs, phytotherapy, or natural supplements.
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Tommaso Caia and Truls E. Bjerklund Johansenb as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
aDepartment of Urology, Santa Chiara Hospital, Largo Medaglie d'Oro,1, 38100 Trento, Italy
bDepartment of Urology, Oslo University Hospital, Oslo, Norway