Clinical and diagnostic evaluation of flank pain in female patients: a retrospective cohort study of 3350 patients.

BACKGROUND/

OBJECTIVES

This study aimed to determine the distribution of confirmed urological diagnoses in female patients presenting with flank pain and to evaluate the diagnostic performance of clinical, laboratory, and imaging parameters in identifying urological pathology.

METHODS

This retrospective cohort study included 3350 female patients (18-65 years) who presented with flank pain at the urology outpatient clinic of Düzce University Hospital between January 2020 and September 2024. Patients were categorized into two groups based on the presence (Group 1, n = 1831) or absence (Group 2, n = 1519) of a confirmed urological diagnosis. Serum creatinine, urinary white blood cells (WBCs), urinary red blood cells (RBCs), and clinical and imaging findings were analyzed. Receiver operating characteristic (ROC) analysis and multivariable logistic regression were performed to assess diagnostic performance.

RESULTS

A confirmed urological diagnosis was identified in 54.7% of patients, with urinary tract infection (27.8%) and urolithiasis (19.8%) being the most frequently documented conditions. Urinary WBC levels demonstrated higher diagnostic performance than serum creatinine (AUC: 0.82 vs. 0.76). In multivariable analysis excluding imaging-derived variables, urinary WBC levels (OR: 3.12, 95% CI: 2.64-3.68, p = 0.01) and serum creatinine (OR: 2.08, 95% CI: 1.72-2.51, p = 0.03) were significantly associated with confirmed urological diagnoses. Combined models incorporating laboratory and clinical parameters showed improved discriminative performance (AUC up to 0.86). Imaging findings, including hydronephrosis and urinary stones, were more frequently observed in patients with confirmed urological diagnoses (p = 0.01).

CONCLUSIONS

Urological conditions constitute a substantial proportion of flank pain presentations in female patients evaluated in a urology outpatient setting. While laboratory and imaging findings provide useful diagnostic information, no single parameter alone is sufficient for accurate differentiation, and a combined clinical and diagnostic approach is required.