The American Urological Association symptom index for benign prostatic hyperplasia as a function of age, volume and ultrasonic appearance of the prostate

PURPOSE: Our study was conducted to reveal quantitatively the relative effects of age and ultrasonic appearance of benign prostatic hyperplasia (BPH) on urinary symptoms as evaluated by the American Urological Association (AUA) symptom index score. MATERIALS AND METHODS: In 929 examinees (732 with a normal prostate and 197 with BPH) on a mass screening program for prostatic diseases using transrectal ultrasonography in Japan, the AUA symptom score was compared to age, prostatic volume and presumed circle area ratio using simple and multiple regression analyses. RESULTS: Simple regression analysis demonstrated the symptom score to correlate significantly with age (R = 0.162, p < 0.0001), prostatic volume (R = 0.072, p = 0.0281) and presumed circle area ratio (R = 0.150, p < 0.0001). However, multiple regression analysis demonstrated that age and presumed circle area ratio were significant independent determinants of the total symptom score. Among 7 symptoms included in the AUA symptom index weak stream and hesitancy scores were not influenced by age, prostatic volume or presumed circle area ratio. CONCLUSIONS: As a parameter representing the degree of BPH in terms of the severity of urinary symptoms, presumed circle area ratio was preferable to prostatic volume. Regression analyses confirmed again that the AUA symptom index was influenced considerably by age and was not specific to BPH.