title: Transition zone index as a risk factor for acute urinary retention in benign prostatic hyperplasia.
abstract: OBJECTIVE
  To examine the efficacy of various parameters obtained by transrectal ultrasonography (TRUS) as predictors of the onset of acute urinary retention in patients with benign prostatic hyperplasia (BPH).
  
  
  METHODS
  From April 1993 to March 1997, 331 men aged 51 to 84 years with symptoms of BPH were enrolled in this study. Among them, 64 patients presented to our clinic because of acute urinary retention. TRUS was used to calculate the transition zone (TZ) volume, the transition zone index (TZ index = TZ volume/total prostate volume), the total prostate volume, and presumed circle area ratio (PCAR). To compare the usefulness of the various indices, the area under the receiver-operator characteristic (ROC) curve was calculated for each index.
  
  
  RESULTS
  There were significant differences in the American Urological Association (AUA) symptom score, total prostate volume, TZ volume, TZ index, and PCAR between patients with and without acute urinary retention, but no significant differences in age and quality of life score. In patients with acute urinary retention, the area under the ROC curve was 0.924 for the TZ index, 0.834 for the TZ volume, 0.753 for the PCAR, 0.684 for the total prostate volume, and 0.628 for the AUA symptom score.
  
  
  CONCLUSIONS
  The TZ index is an accurate predictor of acute urinary retention in patients with BPH and may be a useful method for deciding between surgical intervention and antiandrogen treatment.
authors.affiliation: Department of Urology, Hamamatsu University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kurita
authors.forename: H
authors.initials: H
authors.lastname: Masuda
authors.forename: H
authors.initials: H
authors.lastname: Terada
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Fujita
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011470:Prostatic Hyperplasia / Q000150:complications* / Q000000981:diagnostic imaging*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography; D016055:Urinary Retention / Q000453:epidemiology / Q000209:etiology*