Does evaluation with the international prostate symptom score predict the outcome of transurethral resection of the prostate?

Purpose: We determined the reliability of the International Prostate Symptom Score (I-PSS) in predicting the outcome of transurethral prostatectomy and, therefore, how useful it can be in patient selection for surgery. Materials and Methods: A prospective trial was done of 105 consecutive patients undergoing transurethral prostatectomy at our institution. Patients were assessed with the I-PSS before and 3 months after surgery. Flow rates and preoperative residual volumes also were measured. Results: There was significant postoperative improvement in all parameters of the symptom score and a change in symptom profile. Symptoms remaining with the greatest scores at 3 months postoperatively were frequency, urgency and nocturia. A significant correlation was found between I-PSS and quality of life before and after transurethral prostatectomy, and between postoperative improvement in flow rates and change in I-PSS. Patients with a greater preoperative I-PSS gained the most symptomatic benefit. The positive predictive value of a significant postoperative improvement of at least 7 I-PSS points depended on the preoperative I-PSS criteria applied. With a preoperative I-PSS of more than 17 the positive predictive value was 87% with a corresponding negative predictive value of 71%. Conclusions: The preoperative I-PSS predicted a symptomatic improvement of more than 7 points with high sensitivity. The predictive value depends on the definition of significant improvement (magnitude of I-PSS change) and the level of I-PSS symptoms defined as sufficient to warrant transurethral prostatectomy.