CORRELATION BETWEEN THE INTERNATIONAL PROSTATIC SYMPTOM SCORE AND A PRESSURE-FLOW STUDY IN THE EVALUATION OF SYMPTOMATIC BENIGN PROSTATIC HYPERPLASIA

Purpose: We examined the relationship between the International Prosta tic Symptom Score (I-PSS) and the occurrence of bladder outlet obstruc tion caused by benign prostatic hyperplasia (BPH). Materials and Metho ds: The American Urological Association developed a questionnaire to q uantify the severity of symptoms resulting from BPH. A further questio n relating the impact of BPH to the quality of life was subsequently a dded. This questionnaire has been adopted by the World Health Organiza tion and is known as the I-PSS. There are 4 questions related to obstr uctive symptoms and 3 related to irritative symptoms. Scores of 9 to 7 , 8 to 19 and 20 to 35 represent mild, moderate and severe symptoms, r espectively. During an 18-month interval the I-PSS questionnaire was a dministered to 258 patients 50 to 81 years old (mean age 63 years) wit h BPH. A pressure-flow study was used to determine the presence of bla dder outlet obstruction in 227 patients. Based on the scores, the pati ents were divided into 31 with mild, 116 with moderate and 111 with se vere obstruction. The pressure-flow study was not conducted on patient s with a mild symptom score. Results: Of the patients with a severe sy mptom score 92 (82.9%) had bladder outlet obstruction, compared to 62 (53.4%) with a moderate symptom score. Statistical analysis (Pearson c hi-square test) showed that there was a significant positive correlati on between the symptoms and the presence of bladder outlet obstruction . Thus, when the I-PSS was greater than 28, the probability of bladder outlet obstruction was more than 0.91. Stratification of the results according to the obstructive (9 to 20) and irritative (0 to 15) sympto ms of the I-PSS yielded a significant positive correlation between obs tructive symptoms and the presence of bladder outlet obstruction. Thus , when the obstructive symptom score was greater than 15, the probabil ity of bladder outlet obstruction was greater than 0.91. Conclusions: When the total I-PSS is greater than 28 or the obstructive symptom sco re is greater than 15, a pressure-flow study must be avoided.