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External Validation and Predictive Accuracy Assessment of Guy's Stone Score as a Preoperative Tool for Estimating
Stavros Sfoungaristos1, Amitay Lorber1, Ofer N Gofrit1
1Department of Urology, Hadassah Hebrew University Medical Center , Jerusalem, Israel .
Objective:
To externally validate Guy's stone score system and estimate its predictive accuracy.
Patients And Methods:
An analysis of 282 consecutive patients, who underwent a percutaneous nephrolithotomy, was performed. The association between Guy's stone score and several pre-, intra-, and postoperative parameters was assessed. A univariate and multivariate analysis was conducted to identify the independent predictors for stone-free rates. Area under the curve was used for predictive accuracy estimation.
Results:
Stone burden, multiple stone locations, number of stones, number of implicated caliceal groups, and Guy's stone score were significantly associated with stone-free outcomes. The multivariate analysis showed that Guy's stone score, number of stones, and number of implicated caliceal groups are independent predictors of stone-free status. Receiver operating characteristic curve analysis revealed a significant predictive accuracy for the Guy's stone score.
Conclusions:
The present study externally validated Guy's stone score. Significant predictive ability combined with great predictive accuracy was found.
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