Abstract
In this article, the authors compare four currently available scoring systems for case complexity during percutaneous nephrolithotomy (PCNL); namely, Clinical Research Office of Endourology Society (CROES), S.T.O.N.E., S-ReSC, and Guy's scoring systems. 1 Although there are multiple previous studies externally validating and comparing these scoring systems, 2 –4 this study is unique in that it prospectively evaluated all systems in the same cohort while examining score acquisition times. All scoring systems were significantly associated with and demonstrated a comparable predictive for stone-free status, after a single PCNL session. However, they provided only moderate correlation with complications by Clavien grade.
When considering case complexity, arguably the most important outcomes of interest are stone-free rate and complications that can aid in preoperative risk stratification, planning, and patient counseling. Ideally scoring systems need to be facile to ensure point-of-care utility. Although the CROES grade was best correlated with stone-free status, the area under the curve for all systems demonstrated similar performance. S.T.O.N.E. nephrolithometry 5 had a lower acquisition time compared with the CROES nomogram (105.1 vs 224.4 seconds, p < 0.001) while also being best correlated with complications. The authors provide additional support for the use stone complexity scoring systems and give clarity to the performance of each using practical metrics. This study may help providers progress toward a standardized nomenclature among competing systems.