Noninferiority of Multiplex Polymerase Chain Reaction Compared to Standard Urine Culture for Urinary Tract Infection Diagnosis in Pediatric Patients at Hackensack Meridian Health Children's Hospital Emergency Department.

Objective: To establish the noninferiority of the rapid and sensitive multiplex polymerase chain reaction (M-PCR) method versus standard urine culture (SUC) in pediatric urinary tract infection (UTI) diagnostic testing.

Methods: A United States of America (USA)-based single-center prospective observational study of 44 female and four male patients aged 3-21 years old presenting to a Pediatric Emergency Department in New Jersey with clinically suspected UTI. Urine specimens were primarily collected via midstream voiding. Patients with antibiotic exposure within the week prior to presentation were excluded. Patient demographic data, clinical manifestations, and urinalysis results were recorded. Noninferiority testing comparing M-PCR and SUC was conducted using a method for paired binary data, with a noninferiority margin set at 5%. Noninferiority was concluded if the lower bound of the 95% confidence interval of the difference in detection rates between M-PCR and SUC lies entirely to the right of the value minus the noninferiority margin. All statistical calculations were performed using Python 3.10.12.

Results: The two methods were concordant in two-thirds of cases. Of the 14 M-PCR-positive/SUC-negative discordant specimens, 13 (93%) contained a fastidious and/or emerging uropathogen (A. urinae, A. schaalii, G. vaginalis, C. riegelii, U. urealyticum, Viridans group Streptococci (VGS), and/or Coagulase-negative Staphylococci (CoNS)). Neither symptom presentation nor urinalysis results differed significantly between participants with concordant positive results for UTI diagnosis and those with concordant negative results (non-UTI group).

Conclusion: In this pediatric population, similar to previous findings in an older adult population, M-PCR established not only noninferiority but also superiority over SUC in detecting microorganisms in the urine.