External validation of STONE, modified STONE, and CHOKAI scores for the diagnosis of ureteral stones in the Turkish population

Abstract

Background: Scoring systems seem to be effective in the management of patients with uncomplicated ureteral stones. However, their efficiency may differ by population. Objectives: We aimed to validate STONE, modified STONE, and CHOKAI scores for the diagnosis of ureteral stones in the Turkish population. Methods: We conducted a retrospective chart review between 01 February 2018 and 30 November 2018, in an academic emergency department. Demographics, laboratory findings, and radiologic tests of patients with flank pain were obtained. Computed tomography was used as the gold standard for the diagnosis of ureteral stones. STONE, modified STONE, and CHOKAI scores were calculated for each patient. The performance of the scoring systems was compared in terms of their specificity, sensitivity, positive likelihood ratio, negative likelihood ratio, negative predictive value, and positive predictive value. Results: A total of 157 patients were included in the study. The mean age was 38.47 ± 14.87 years, and 103 (65.6%) of the patients were males. The prevalence of ureteral stones was 84.0%, 88.9%, and 85.0% in the high-risk patients and 12%, 9.4%, and 22.7% in the low-risk patients for the STONE, modified STONE, and CHOKAI scores, respectively. Area under the curve values for the STONE, modified STONE, and CHOKAI scores were 0.776 (p = 0.001; 0.692–0.860 95% confidence interval), 0.825 (p < 0.001; 0.749–0.901 95% confidence interval), and 0.869 (p < 0.001; 0.806–0.932 95% confidence interval), respectively. The specificity and sensitivity values of STONE, modified STONE, and CHOKAI scores for the diagnosis of ureteral stones were 64.71, 71.70; 70.59, 87.74; and 66.67, 90.57, respectively. Conclusion: The CHOKAI score displayed the best performance compared to STONE and modified STONE in diagnosing ureteral stones in the Turkish population.