Beyond bacteremia: clinical phenotypes and determinants of mortality in hospitalized adults with community-acquired urinary tract infection.

Background: Community-acquired urinary tract infection (CA-UTI) is a leading source of bacteremia and sepsis in adults, yet the determinants of bloodstream invasion and short-term mortality remain incompletely defined. In particular, the relative contributions of age, comorbidity, antimicrobial resistance, and acute organ dysfunction are uncertain. Methods: We conducted a retrospective cohort study of consecutive adults hospitalized with CA-UTI at a tertiary hospital in Türkiye between January 2023 and June 2025. Clinical, laboratory, microbiological, and outcome data were abstracted. Multivariable logistic regression was used to identify predictors of concomitant bacteremia and 30-day all-cause mortality in the overall cohort and in the bacteremic subgroup. An eight-item unweighted risk-factor count score (male sex, short symptom duration, prior extended-spectrum β-lactamase-producing and carbapenem-resistant organisms colonization or infection, Charlson Comorbidity Index (CCI) ≥ 2, diabetes mellitus, qSOFA ≥ 2, C-reactive protein > 100 mg/L, procalcitonin ≥ 0.5 ng/mL) was derived to predict bacteremia, and its discrimination was assessed with ROC analysis. Results: Among 358 adults with CA-UTI, 117 (32.7%) had concomitant bacteremia. In the multivariable model, independent predictors of bacteremia included male sex, shorter symptom duration, prior extended-spectrum β-lactamase-producing and carbapenem-resistant organisms colonization or infection, CCI ≥ 2, diabetes mellitus, qSOFA ≥ 2, C-reactive protein > 100 mg/L, and procalcitonin ≥ 0.5 ng/mL. The eight-item risk-factor count showed a strong gradient in bacteremia prevalence (3.8% with 0-1 factors, 24.7% with 2-3, and 75.0% with ≥ 4) and good discrimination (AUROC 0.83 for the full model and 0.80 for the simplified score; DeLong p ≈ 0.3). Overall, 30-day mortality was 6.1% (22/358) and higher in bacteremic than non-bacteremic CA-UTI (9.4% vs. 4.6%). In the whole cohort, both bacteremia and qSOFA score ≥ 2 were independent predictors of 30-day mortality. Within the bacteremic subgroup, qSOFA score ≥ 2 was identified as the sole independent predictor. Conclusion: In adults hospitalized with CA-UTI, bacteremia identifies a high-risk clinical phenotype but is not the sole determinant of prognosis. Bacteremia is a marker of severity, whereas organ dysfunction, as captured by qSOFA, is the main driver of mortality. A simple eight-item bedside score demonstrated promising performance in predicting bacteremia but requires external validation before its routine use in clinical triage.