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

Abstract 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 explicitly 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 verified-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), to test whether it can identify UTI likelihood in this population. Methods The reference standard was applied to 224 samples from 99 adults with NLUTD due to SCI/D using IC, all verified asymptomatic by the Urinary Symptom Questionnaire for Neurogenic Bladder–Intermittent Catheter (USQNB-IC) 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 conservative interpretation, 40.2% of samples were classified No UTI, 21.9% Possible UTI, and 37.9% Probable UTI; under inclusive interpretation, 11.6% No UTI, 38.4% Possible UTI, and 50.0% Probable UTI. No sample reached Definite UTI — a structural consequence of the empty systemic domain. Conclusions The consensus reference standard classifies 38–50% of fully asymptomatic NLUTD-IC samples as Probable UTI, a floor estimate that could only rise if blood markers were available. This confirms the 2024 framework’s own prediction that a separate standard is needed for populations with altered symptom expression and baseline-positive urinary markers.