title: Implications of different nephrolithometry scoring systems on clinical practice of endourologists: An international web-based survey.
abstract: OBJECTIVE
  To assess the implications of different nephrolithometry scoring systems (NLSS) on clinical practice of endourologists to predict stone-free status (SFS) after percutaneous nephrolithotomy (PCNL).
  
  
  METHODS
  A web-based survey was sent to members of the Endourological Society. Demographic and practice pattern data were collected. Multiple-choice and open-ended questions were used to assess awareness about the NLSS and their authentic use in clinical practice. Surgeon preferences and limitations of NLSS and how to overcome them were asked.
  
  
  RESULTS
  In all, there were 162 responses, including 17 (10.5%) respondents who were not aware of NLSS. Most respondents (82.1%) denied the efficacy of NLSS in predicting SFS after PCNL. Of 145 respondents who were aware of NLSS, 85.5% did not use them in clinical practice. Endourologists aged 40-60 years (P < 0.001), in practice for 10-20 years (P = 0.003), those performing 100-200 PCNLs/year (P = 0.02), and those from North America (P < 0.001) seemed to use NLSS more frequently. In all, 50% of respondents preferred not to use any NLSS, while 29% chose the S.T.O.N.E followed by the Guy's Stone Score (10.3%) and The Clinical Research Office of the Endourology Society (CROES) nomogram (8.3%). Inconsistency and variability among different NLSS were the main drawbacks reported by 82% of 89 respondents. The need for high-level evidence for NLSS through direct randomised prospective comparison was recommended by 24.8% of respondents who answered that question.
  
  
  CONCLUSIONS
  There is a lack of compliance and acceptance of different NLSS in clinical practice among endourologists. Inconsistency and inaccuracy in predicting SFS after PCNL limits their incorporation into clinical practice. However, the results of this study might not be generalisable due to the selection bias resulting from the geographical distribution of the respondents and the heterogeneity in surgical expertise. Therefore, randomised prospective direct comparisons and validation of these systems are recommended.
authors.affiliation: Department of Urology, Suez Canal University, Ismailia, Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Elkoushy
authors.affiliation: Department of Urology, Suez Canal University, Ismailia, Egypt.
authors.forename: Adel H
authors.initials: AH
authors.lastname: Metwally
authors.affiliation: Department of Urology, Benha University, Benha, Egypt.
authors.forename: Yasser A
authors.initials: YA
authors.lastname: Noureldin
keywords: CROES, the Clinical Research Office of the Endourology Society; Clinical practice pattern; Endourology; NCCT, non-contrast CT; NLSS, nephrolithometry scoring systems; Nomogram; Outcome; PCNL, percutaneous nephrolithotomy; Percutaneous nephrolithotomy; S-ReSC, Seoul National University Renal Stone Complexity; S.T.O.N.E., Stone Size, Tract length, Obstruction/hydronephrosis, Number of involved calyces, Essence/Hounsfield units; SFS, stone-free status