AbstractAimTo study the correlation between non‐invasive urodynamic data, the International Prostate Symptom Score (IPSS) and the prostate volume.Materials and MethodsData of 667 healthy volunteers participating in a longitudinal study of changes in urinary bladder contractility secondary to BPE were analyzed. The prostate volume was assessed by transabdominal ultrasonography. Uroflowmetry followed to verify if a minimum free flow rate of 4.5 ml/sec could be achieved. While (re)filling the bladder by drinking, the subjects completed the Dutch version of the IPSS. Next, the bladder pressure was non‐invasively measured using the condom catheter method. The urethral resistance (URR) was calculated from the maximum condom pressure and the maximum free flow rate.ResultsThe IPSS ranged from 0 to 29, (6.1 ± 4.8) (mean ± SD), whereas the prostate volumes ranged from 8 to 140 cm3, (34 ± 18). Twenty eight percent (185/667) of the subjects had a non‐invasively quantified high URR and a significantly higher IPSS (7.3 ± 5.2) than those with a low URR (IPSS (5.7 ± 4.6)), Mann–Whitney U‐test: P < 0.001. The IPSS and the URR were significantly correlated, Spearman's rho (ρ) = 0.20, P < 0.001. A significant difference between the prostate volumes, 36 ± 21 cm3 in the high URR versus 33 ± 17 cm3 in the low URR group, was not found, P = 0.18.ConclusionsA weak though statistically significant correlation was found between the non‐invasively quantified URR and the IPSS. This suggests that an elevated resistance is a necessary, but not a sufficient condition for lower urinary tract symptoms (LUTS). No correlation was found between the URR and the prostate volume. © 2004 Wiley‐Liss, Inc.