title: The diagnosis of benign prostatic obstruction: Development of a clinical nomogram.
abstract: OBJECTIVE
  To develop a nomogram predicting benign prostatic obstruction (BPO).
  
  
  METHODS
  We included in this study 600 men with lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) who underwent standardized pressure flow studies (PFS) between 1996 and 2000. Complete clinical and urodynamic data were available for all patients. Variables assessed in univariate and multivariate logistic regression models consisted of IPSS, PSA, prostate size, maximal urinary flow rate (Qmax) at free flow, residual urine (RU), and bladder wall thickness (BWT). These were used to predict significant BPO (defined as a Schäfer grade ≥ 3 in PFS).
  
  
  RESULTS
  A preliminary multivariate model, including IPSS, Qmax at free flow and RU, suggested that only Qmax at free flow was a statistically significant predictor of BPO (P = 0.00) with a predictive accuracy (PA) of 82%. Further development of the multivariate model showed how the inclusion of BWT did not increase PA. Only transitional zone volume (TZV) proved to be an additional statistically significant predictor for BPO (P = 0.00). The combination of Qmax at free flow and TZV demonstrated a PA of 83.2% and were included in the final nomogram format.
  
  
  CONCLUSIONS
  We developed a clinical nomogram, which is both accurate and well calibrated, which can be helpful in the management of patients with LUTS and BPE. External validation is warranted to confirm our findings.
authors.affiliation: Department of Urology, Sant' Andrea Hospital "La Sapienza,", Rome, Italy.
authors.forename: Cosimo
authors.initials: C
authors.lastname: De Nunzio
authors.affiliation: Department of Urology, Urology Clinic, Second University of Naples, Naples, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Autorino
authors.affiliation: Department of Urology, Urologische Klinik, Universitätsspital Basel, Basel, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bachmann
authors.affiliation: Department of Urology, Vita-Salute University San Raffaele, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.affiliation: Department of Urology, London Clinic, London, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Carter
authors.affiliation: Department of Urology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Chun
authors.affiliation: Department of Oncological and Surgical Sciences, Urology Clinic, University of Padua, Padua, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Novara
authors.affiliation: Department of Urology, M. Sklodowska-Curie Memorial Cancer Center, Warsaw, Poland.
authors.forename: Roman
authors.initials: R
authors.lastname: Sosnowski
authors.affiliation: Department of Urology, Addenbrookes Hospital, Cambridge, United Kingdom.
authors.forename: Nickesh
authors.initials: N
authors.lastname: Thiruchelvam
authors.affiliation: Department of Urology, Sant' Andrea Hospital "La Sapienza,", Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Tubaro
authors.affiliation: Department of Urology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Ahyai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003661:Decision Support Techniques; D006801:Humans; D016015:Logistic Models; D059411:Lower Urinary Tract Symptoms / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D049451:Nomograms; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011312:Pressure; D011379:Prognosis; D011470:Prostatic Hyperplasia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D001743:Urinary Bladder / Q000503:physiopathology*; D014563:Urodynamics
keywords: benign prostatic hyperplasia; bladder prostatic obstruction; detrusor wall thickness; intravesical prostatic protrusion; prostate; prostate volume