title: Re-categorisation of male lower urinary tract symptoms based on the international prostate symptom score questionnaire.
abstract: OBJECTIVE
  The purpose of this study was to develop a new sub-classification system for male lower urinary tract symptoms (LUTS)-mild, moderate and severe-using the conventional International Prostate Symptoms Score (I-PSS).
  
  
  METHODS
  From October 2007 to March 2012, a total of 2234 male patients (≥ 50 years old) presenting with LUTS were enrolled in this study. Patients were sorted according to their I-PSS (ranging from 1 to 35 points) and divided into three groups based on their quality of life (QoL) score. A chi-square automatic interaction detection (CHAID) algorithm, based on adjusted significance testing, was used. The Kappa coefficient was calculated for the agreement of original and new categorisation.
  
  
  RESULTS
  Mean total I-PSS and QoL scores were 11.0 and 2.9 respectively. According to the original classification, 838 patients (38.6%) had mild, 1053 (48.5%) had moderate and 282 (13.0%) had severe symptoms. After the CHAID algorithm was applied, the scores were re-categorised as 'mild' (1-6 points), 'moderate' (7-21 points) and 'severe' (22-35 points). The overall model was able to correctly predict whether an I-PSS was associated with mild, moderate or severe symptoms, with 70.1% accuracy. According to this new classification, 704 patients (32.4%) were shown to have mild, 1255 (57.8%) to have moderate and 214 (9.8%) to have severe LUTS. The agreement of conventional and new categorisation is very strong (Kappa coefficient = 0.84).
  
  
  CONCLUSIONS
  Conventional categorisation of LUTS by I-PSS needs to be updated and the category of moderate LUTS should be broadened.
authors.affiliation: Department of Urology, College of Medicine, Soonchunhyang University, Seoul Hospital, Seoul, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
authors.forename: M H
authors.initials: MH
authors.lastname: Lee
authors.forename: S W
authors.initials: SW
authors.lastname: Doo
authors.forename: W J
authors.initials: WJ
authors.lastname: Yang
authors.forename: Y S
authors.initials: YS
authors.lastname: Song
authors.forename: B W
authors.initials: BW
authors.lastname: Yoo
authors.forename: S-S
authors.initials: SS
authors.lastname: Kwon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D059411:Lower Urinary Tract Symptoms / Q000145:classification* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires