Comparative analysis of RIRS scoring system and Resorlu Unsal Stone Score (RUSS) for predicting stone free rate after retrograde intrarenal surgery

Objectives: To compare the predictive ability of the RIRS scoring system and the RUSS in predicting stone-free rate (SFR) after retrograde intrarenal surgery (RIRS), and to evaluate the sensitivity and specificity of both scoring systems, as well as their association with complications. Methods: This retrospective study was carried out on patients who underwent RIRS for renal stones between July 2017 and July 2020. Two scoring systems were used to assess the degree of difficulty of the procedure: the RIRS scoring system and the RUSS. The predictive ability of the two scoring systems were compared using receiver operating characteristic (ROC) analysis and calculated the sensitivity and specificity of each system. The association between the scoring systems and complications were determined using logistic regression. Results: A total of 200 patients were included in the study with a mean age of 50.13± 8.98 years and 120 (60%) were males. The results showed a significant AUC of 0.669 for the RIRS score (P<0.001), 95% CI (0.599 to 0.734). The sensitivity and specificity were 76.51 % and 85.7%, respectively. In contrast, the RUSS score revealed a non-significant unsatisfactory AUC of 0.480 (P = 0.845), with a 95% confidence interval ranging from 0.438 to 0.581.