Utility of catheterized specimens in reducing overdiagnosis of urinary tract infections in women.

Aims: To evaluate the utility of catheterized samples in reducing overdiagnosis of UTI based on voided specimens among patients presenting with a range of urinary symptoms. We also aimed to determine variables that may modify the predictive value of the voided midstream urine culture.
Methods: Patient charts were reviewed to identify female patients referred to our voiding dysfunction clinic with a range of complaints warranting urine studies (5/2014-8/2016). Patients with a positive voided urine culture who also had a catheterized urine culture in our system were included. Multiple logistic regression analysis was performed to identify patient characteristics associated with a negative catheterized specimen despite a positive voided specimen.
Results: One hundred and seven women were included in the study. Eighty percent of the cohort was post-menopausal. Although all patients had positive voided specimens, only 53 (49.5%) had positive catheterized specimens. On multivariate analysis negative nitrites on clean catch UA was a significant predictor of a negative catheterized sample (adjusted OR 8.9, 95%CI 2.2-43.7, P = 0.003). WBC/HPF <10 on clean catch UA trended towards significance (adjusted OR 4.72, 95%CI 1.1-26.1, P = 0.05).
Conclusions: Relying on clean catch urine samples may lead to significant over-diagnosis of UTIs. Our study suggests that in female patients who have vague symptoms of UTI, obtaining catheterized specimens may be beneficial in avoiding the overdiagnosis of UTIs and the overuse of antibiotics. Larger, prospective studies testing our hypothesis are necessary, and would greatly assist in establishing clinical practices that reduce the amount of antibiotics inappropriately prescribed.
(© 2018 Wiley Periodicals, Inc.)