Use of the International Prostate Symptom Score voiding-to-storage subscore ratio in assessing lower urinary tract symptoms

Abstract

The International Prostate Symptoms Score (IPSS) questionnaire has been used for decades to evaluate the severity of lower urinary tract symptoms (LUTS)/benign prostatic obstruction, and has also been applied to other conditions causing LUTS. However, the total IPSS correlates poorly with benign prostatic obstruction and overactive bladder, and is unreliable for establishing a definitive diagnosis. Although the clinical symptoms are not reliable in establishing the diagnosis, patients with bladder outlet-related lower urinary tract disease (LUTD) tend to have more prominent voiding symptoms and those with bladder-related LUTD tend to have more prominent storage symptoms. Measuring IPSS subscores and calculating the IPSS voiding-to-storage subscore ratio (IPSS-V/S) constitute a simple and reliable method to differentiate failure-to-void (bladder outlet-related) LUTD from failure-to-storage (bladder-related) LUTD. The IPSS-V/S is a better predictor of bladder outlet-related LUTD than the total IPSS, whether used alone or in combination with the total prostate volume and maximal flow rate. The IPSS-V/S can also be used as a guide for the initial treatment of male LUTS, especially by nonurologists. First-line antimuscarinic monotherapy for males with an IPSS-V/S of ≤1 is safe and effective. The IPSS may be used to evaluate female LUTD. The IPSS-V/S was found to have the highest area under the receiver-operating characteristic curve for predicting voiding LUTD when compared with other noninvasive methods. This ratio is also a useful indicator to initiate treatment of voiding dysfunction in women.