Objective: This study investigates the potential discrepancy between post-void residual urine (PVR) measurements obtained immediately after uroflowmetry and those reflecting patients’ usual voiding patterns, aiming to evaluate the reliability of immediate post-test measurements.Methods: This prospective study included 110 men >45 years with lower urinary tract symptoms.

PVR was measured by transabdominal ultrasonography immediately after uroflowmetry (PVR0), on day 1 (PVR1), and day 7 (PVR7). Patients were grouped by pre-void bladder volume: 500 mL. Uroflowmetric parameters, prostate volume, PSA, IPSS, BMI, and detrusor thickness were recorded.Results: The mean age was 60.32±6.93 years; mean prostate volume 44.84±20.44 mL.

In the uroflowmetry test, the mean values for Qmax, Qave, and voided volume were detected as 15.83±7.00 mL/sec, 6.21±2.62 mL/sec, and 304.15±157.81 mL, respectively. The mean bladder volume was 408.30±191.53 mL. When stratified into three groups based on bladder volume ( 500 mL), 26.4% of the patients had a bladder volume 500 mL.

The mean PVR0, PVR1, and PVR7 were 104.12±108.51 mL, 33.74±82.54 mL, and 19.59±47.91 mL, respectively. A comparative analysis of PVR0, PVR1, and PVR7 revealed a statistically significant decreasing trend over time: PVR7