title: [Evaluation of psychometric properties of Japanese version of international prostate symptom score and BPH impact index].
abstract: OBJECTIVE
  To evaluate psychometric properties of the Japanese version of International Prostate Symptom Score (IPSS) and BPH Impact Index (BII).
  
  
  METHODS
  The translated IPSS and BII questionnaires were administered to 103 patients with benign prostatic hyperplasia and 23 asymptomatic men. In 82 patients the questionnaires were repeated 2 weeks later to examine reproducibility. Further 2 weeks later 21 out of 82 patients responded to the questionnaires asking symptoms during the last week rather than during the last month. To evaluated responsiveness the questionnaires were repeated after treatment in 22 patients. Internal consistency, construct validity and criterion validity were examined by proper statistic methods.
  
  
  RESULTS
  Reproducibility was good to excellent with weighted kappa more than 0.62 for all items. It was not significantly affected by age, symptom severity, institution type, or whether the patients were asked symptoms during the last week or during the last month. Internal consistency was also good with Cronbach's alpha more than 0.83. Principle component analysis identified 2 components in IPSS and a single component in BII, with all the items contributing to the first component. Most items had significant correlation with external criteria including maximum flow rate, residual urine volume or prostate volume. The scores of patients were clearly larger than asymptomatic men and obviously reduced after receiving therapies.
  
  
  CONCLUSIONS
  Japanese translations of IPSS and BII were shown to be reliable, valid and one-dimensional instruments in the Japanese patients. They would be equivalent to the original English questionnaires.
authors.affiliation: Department of Urology, University of Tokyo.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Homma
authors.forename: Taiji
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Kousaku
authors.initials: K
authors.lastname: Yasuda
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Ozono
authors.forename: Masaki
authors.initials: M
authors.lastname: Yoshida
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D005069:Evaluation Studies as Topic; D006305:Health Status Indicators; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011470:Prostatic Hyperplasia / Q000523:psychology; D011594:Psychometrics; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires / Q000592:standards*; D014177:Translations