2. Practice and urodynamic evaluation

As a routine practice, patients who present with LUTS were interviewed about the detailed history of LUTS/medications and underwent physical examination, free uroflowmetry and post-void residual (PVR) measurement. For symptom evaluation, they documented an International Prostate Symptom Score, Overactive Bladder Symptom Score, and a 3-day frequency-volume chart. A free uroflowmetry (DABA; Endo tech, Seongnam, Korea) along with a measurement of PVR volume (BladderScan™ BVI-3000; Diagnostic Ultrasound, Bothell, WA, USA) were performed prior to urodynamic evaluation. The result with a higher maximum flow rate (Q_max) was selected from two sets of free uroflowmetry with a voided volume ≥150 mL [10]. Data of free uroflowmetry with a voided volume below 150 mL were not included in the present study.

Urodynamic examinations were in accordance with the guidelines of the International Continence Society (ICS) [11] and a multichannel urodynamic measurement (UD-2000; Medical Measurement Systems, Enschede, The Netherlands) was carried out. The medications that could possibly affect voiding function were discontinued for at least 3 days before the examination.