Can a 45-minute urine test help manage suspected uncomplicated UTIs?

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The PA-100 AST system (Sysmex®) is a point-of-care test that uses a fixed threshold to detect bacteria in urine and performs antimicrobial susceptibility testing (AST) within 45 minutes. The study evaluated its diagnostic accuracy and perceived clinical utility for diagnosing uncomplicated urinary tract infection (uUTI) in people assigned female at birth.

This prospective multicentre diagnostic accuracy study took place in four primary care practices in Germany. Urine samples from adult female patients with uUTI symptoms were tested with the PA-100 AST as the index test and standard laboratory urine culture as the reference standard. General practitioners reported the perceived clinical utility. The analysis included 109 patients, with a median age of 59 years and an interquartile range of 43–72. Bacteriuria prevalence was 63%.

For bacterial detection, sensitivity was 86% (95% confidence interval [CI] 67–88) and specificity was 80% (95% CI 63–93). The positive predictive value was 88% (95% CI 80–96), and the negative predictive value was 76% (95% CI 46–77).

For AST, overall categorical agreement was 84% for ciprofloxacin, 87% for fosfomycin, 94% for trimethoprim and 95% for nitrofurantoin. Overall sensitivity for identifying non-susceptible pathogens was 74% (11/15), but was particularly low for ciprofloxacin at 40% (2/5). Of 15 resistant isolates, the PA-100 AST misclassified four (27%) as susceptible.

GPs reported that results influenced prescribing in 25% of consultations, split equally between starting antibiotics after initially withholding them (“step-up”) and withholding antibiotics after initially considering treatment (“step-down”). They also reported improved communication and diagnostic confidence, and said the test could readily be integrated into routine workflow.

The researchers concluded that the PA-100 AST showed moderate diagnostic accuracy and may support management of suspected uUTI in primary care. Its relatively low negative predictive value in this study population limits its ability to rule out bacteriuria. The test had a modest impact on prescribing decisions, and further research is needed to determine its effectiveness in optimizing antibiotic use.