The potential impact of biomarker-guided triage decisions for patients with urinary tract infections

Current guidelines provide limited evidence as to which patients with urinary tract infection (UTI) require hospitalisation. We evaluated the currently used triage routine and tested whether a set of criteria including biomarkers like proadrenomedullin (proADM) and urea have the potential to improve triage decisions.

Consecutive adults with UTI presenting to our emergency department (ED) were recruited and followed for 30 days. We defined three virtual triage algorithms, which included either guideline-based clinical criteria, optimised admission proADM or urea levels in addition to a set of clinical criteria. We compared actual treatment sites and observed adverse events based on the physician judgment with the proportion of patients assigned to treatment sites according to the three virtual algorithms. Adverse outcome was defined as transfer to the intensive care unit (ICU), death, recurrence of UTI or rehospitalisation for any reason.

We recruited 127 patients (age 61.8 ± 20.8 years; 73.2 % females) and analysed the data of 123 patients with a final diagnosis of UTI. Of these 123 patients, 27 (22.0 %) were treated as outpatients. Virtual triage based only on clinical signs would have treated only 22 (17.9 %) patients as outpatients, with higher proportions of outpatients equally in both biomarker groups (29.3 %; p = 0.02). There were no significant differences in adverse events between outpatients according to the clinical (4.5 %), proADM (2.8 %) or urea groups (2.8 %). The mean length of stay was 6.6 days, including 2.2 days after reaching medical stability.

Adding biomarkers to clinical criteria has the potential to improve risk-based triage without impairing safety. Current rates of admission and length of stay could be shortened in patients with UTI.