Discrepancies Between IPSS, PVR, and Uroflowmetry: Implications for the Management of Lower Urinary Tract Symptoms

Background/Objectives: To evaluate the discrepancies between the International Prostate Symptom Score (IPSS) and objective measures—uroflowmetry (Qmax) and post-void residual (PVR) volume—in men with lower urinary tract symptoms (LUTS), and to assess the implications for diagnosis and treatment planning. Methods: This retrospective study analyzed data from 414 men across three urology clinics who completed both IPSS and uroflowmetry between April 2023 and September 2024. IPSS total and subscores were categorized by severity and compared with Qmax (<15 vs. ≥15 mL/s) and PVR (<250 vs. ≥250 mL). Two exploratory discordance patterns were defined: a ‘bother-dominant’ pattern (moderate-to-severe IPSS with normal Qmax or PVR) and an ‘unrecognized voiding dysfunction’ pattern (mild IPSS with abnormal Qmax or PVR). Results: Among patients with severe total IPSSs, 8.7% had Qmax ≥ 15 mL/s, consistent with a ‘bother-dominant’ pattern, and 8.7% of those with mild scores had Qmax < 15 mL/s, consistent with an ‘unrecognized voiding dysfunction’ pattern. When moderate scores were included, the ‘bother-dominant’ pattern was observed in 27.8% and the unrecognized voiding dysfunction pattern in 36.0%. For PVR, 40.1% of patients with severe IPSSs had PVR < 250 mL (‘bother-dominant’ pattern), while the unrecognized voiding dysfunction pattern with elevated PVR was rare (≤1.3%). Discrepancies were also observed across voiding and storage subscores and individual items, such as incomplete emptying and weak stream. Conclusions: There is frequent discordance between subjective symptom severity and objective urodynamic findings in men with LUTS. Sole reliance on IPSS may lead to misclassification and inappropriate treatment. Incorporating Qmax and PVR into routine evaluation may enhance diagnostic accuracy and support more personalized management strategies.