Correlation of Age and Laboratory Parameters with Urine Flow Cytometry and Culture Results in Patients with Urinary Tract Infections

Background: The diagnosis of urinary tract infection (UTI) remains a clinical challenge, with urine culture as the gold standard. In developing countries like Bosnia and Herzegovina, a high prevalence of antimicrobial resistance and frequent empirical treatment pose significant clinical challenges. Automated urine flow cytometry has emerged as a rapid tool to optimize diagnostic processes. Objectives: To determine the correlation of age, gender, and laboratory parameters—such as white blood cell (WBC) count, neutrophil count, and C-reactive protein (CRP)—with both urinary bacterial counts and urine culture results. Methods: This retrospective study analyzed 200 adult patients (≥18 years) with symptoms suggestive of UTI at the University Clinical Center Tuzla. Data on age, gender, WBC, neutrophils, CRP, and urine flow cytometry (Sysmex UF-4000) were collected. Statistical analysis was performed using R software (version 4.5.1), utilizing logistic regression models via the ‘glm’ function to identify independent predictors, with statistical significance set at p < 0.05. Results: The mean age of the population was 68.61 ± 15.19 years. Logistic regression demonstrated that WBC count (OR = 1.06, p = 0.004), neutrophil count (OR = 1.04, p = 0.014), and patient age (OR = 1.03, p = 0.001) were significant independent predictors of UTI. Furthermore, patients with a urinary bacterial count > 1200/μL had 83 times higher odds of a positive urine culture (OR = 83, 95% CI 32.25–200, p < 0.001). Conversely, CRP levels and gender were not significant predictors (p > 0.05). Conclusions: Patient age, WBC, and neutrophil counts are key factors for predicting UTIs. Integrating these parameters with urine flow cytometry bacterial counts can significantly enhance diagnostic accuracy and rapid screening in clinical practice.