title: Evaluation and comparison of urolithiasis scoring systems used in percutaneous kidney stone surgery.
abstract: OBJECTIVE
  Contemporary predictive tools for percutaneous nephrolithotomy outcomes include the Guy stone score, S.T.O.N.E. nephrolithometry and the CROES nephrolithometric nomogram. We compared each scoring system in the same cohort to determine which was most predictive of surgical outcomes.
  
  
  METHODS
  We retrospectively reviewed the records of patients who underwent percutaneous nephrolithotomy between 2009 and 2012 at a total of 3 academic institutions. We calculated the Guy stone score, the S.T.O.N.E. nephrolithometry score and the CROES nephrolithometric nomogram score based on preoperative computerized tomography images. A single observer at each institution reviewed all images and assigned scores. Univariate and multivariate analysis was done to determine the most predictive scoring system.
  
  
  RESULTS
  We enrolled 246 patients in study. In stone-free patients vs those with residual stones the mean Guy score was 2.2 vs 2.7, the mean S.T.O.N.E. score was 8.3 vs 9.5 and the mean CROES nomogram score was 222 vs 187 (each p <0.001). Logistic regression revealed that the Guy, S.T.O.N.E. nephrolithometry and CROES nomogram scores were significantly associated with stone-free status (p = 0.02, 0.004 and <0.001, respectively). The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss (p <0.0001 and 0.03) and length of stay (p = 0.03 and 0.009, respectively). The CROES nomogram did not predict estimated blood loss or length of stay.
  
  
  CONCLUSIONS
  All scoring systems and the stone burden equally predicted stone-free status. The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss and length of stay. A single scoring system should be adopted to unify reporting.
authors.affiliation: Department of Urology, University of California-Irvine, Orange, California.
authors.forename: Kevin
authors.initials: K
authors.lastname: Labadie
authors.affiliation: Department of Urology, University of California-Irvine, Orange, California.
authors.forename: Zhamshid
authors.initials: Z
authors.lastname: Okhunov
authors.affiliation: Department of Urology, University of Florida, Gainesville, Gainesville, Florida.
authors.forename: Arash
authors.initials: A
authors.lastname: Akhavein
authors.affiliation: Smith Institute for Urology, North Shore LIJ Health System, New Hyde Park, New York.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Moreira
authors.affiliation: Department of Urology, University of California-Irvine, Orange, California.
authors.forename: Jorge
authors.initials: J
authors.lastname: Moreno-Palacios
authors.affiliation: Department of Urology, University of California-Irvine, Orange, California.
authors.forename: Michael
authors.initials: M
authors.lastname: Del Junco
authors.affiliation: Smith Institute for Urology, North Shore LIJ Health System, New Hyde Park, New York.
authors.forename: Zeph
authors.initials: Z
authors.lastname: Okeke
authors.affiliation: Department of Urology, University of Florida, Gainesville, Gainesville, Florida.
authors.forename: Vincent
authors.initials: V
authors.lastname: Bird
authors.affiliation: Smith Institute for Urology, North Shore LIJ Health System, New Hyde Park, New York.
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Smith
authors.affiliation: Department of Urology, University of California-Irvine, Orange, California. Electronic address: landmanj@uci.edu.
authors.forename: Jaime
authors.initials: J
authors.lastname: Landman
mesh_terms: D000704:Analysis of Variance; D003950:Diagnostic Techniques, Urological; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D052878:Urolithiasis / Q000175:diagnosis
keywords: kidney; nephrostomy; nomograms; percutaneous; research design; urolithiasis