The 2024 International Consensus Reference Standard for Urinary Tract Infection (UTI) Research fails in Neurogenic Bladder without UTI symptoms

Background. The 2024 international reference standard for urinary tract infection (UTI) research scores four domains, symptoms and signs; systemic criteria; pyuria; and culture to classify samples as No UTI, Possible UTI, Probable UTI, or Definite UTI. It identifies spinal cord injury (SCI) as a condition of impaired symptom perception, and states that catheter-associated UTI requires a separate standard. We applied it to confirmed-asymptomatic samples from adults with neurogenic lower urinary tract dysfunction (NLUTD) due to spinal cord injury or disease (SCI/D) who use intermittent catheterization (IC). Methods. The reference standard was applied to 222 samples from 96 adults with NLUTD due to SCI/D using IC, for all of which the participant confirmed, using the Urinary Symptom Questionnaire for Neurogenic Bladder-Intermittent Catheter (USQNB-IC), that they had been asymptomatic at sampling and for 72 hours prior. Because no participant was febrile and no blood markers are drawn in this population, the systemic-criteria domain scored zero for every sample; the reported classifications are therefore a floor. Pyuria was scored under conservative and inclusive interpretations of categorical urinary white blood cell (WBC) bins. Results. Under the conservative interpretation, 38.7% of samples were classified No UTI, 22.5% Possible UTI, and 38.7% Probable UTI; under the inclusive interpretation, 8.1% No UTI, 40.5% Possible UTI, and 51.4% Probable UTI. No sample reached Definite UTI, a structural consequence of the empty systemic domain. Of the samples that met the pyuria entry threshold, 136 of 136 (conservative) and 204 of 206 (inclusive) were classified Possible or Probable UTI: meeting the entry threshold determined the classification. Conclusions. The consensus reference standard classifies 61-92% of confirmed-asymptomatic NLUTD-IC samples as Possible or Probable UTI, and 39-51% as Probable UTI, a floor estimate that could only rise if blood markers were available. This confirms the framework's prediction that a separate standard is needed for populations with altered symptom expression and baseline-positive urinary markers.