https://doi.org/10.4081/aiua.2025.14265
Performance of ‘Triple-D’ and ‘Quadruple-D’ scores compared to a regression-based predictive model for treatment outcomes in extracorporeal shock wave lithotripsy
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Published: 22 October 2025
Background: Extracorporeal shock wave lithotripsy (ESWL) is a widely utilized, noninvasive treatment for renal and ureteric stones. Accurate prediction of treatment outcomes is essential for improving patient counseling and optimizing clinical management. Established scoring systems, such as the ‘Triple-D’ score – which incorporates stone Density, Diameter, and skin-to-stone Distance –and the ‘Quadruple-D’ score – which adds factors like stone location or hydronephrosis status – are used to stratify patients by risk. However, these tools have limitations in predictive accuracy. This study aimed to evaluate and compare the predictive performances of the Triple-D and Quadruple-D scores against a novel regression-based model for ESWL outcomes.
Methods: A retrospective study was conducted on 1,000 adult patients treated with ESWL using the Dornier Compact Delta® III Pro lithotripter from May 2022 to November 2023. Key predictors of ESWL failure were identified using multivariable logistic regression with internal validation. Predictive performances were compared using receiver operating characteristic (ROC) analysis, with statistical differences assessed by DeLong’s test. Model calibration and clinical utility were examined through calibration plots and decision curve analysis (DCA).
Results: ESWL treatment success was achieved in 87.5% of patients. Independent predictors of failure included prior urologic intervention (adjusted odds ratio [aOR] 2.64, 95% CI 1.75-3.99), multiple stones (aOR 0.45, 95% CI 0.24-0.77), higher stone density (per 100 Hounsfield Units increase; p<0.001), and increased skin-to-stone distance (per cm; aOR 1.18, 95% CI 1.06-1.30). The regression-based model showed superior discrimination (AUC 0.92) compared to the Quadruple-D (AUC 0.81, p=0.01) and Triple-D (AUC 0.72, p<0.001) scores. Calibration and DCA confirmed the model’s improved accuracy and clinical benefit.
Conclusions: The regression-based model outperforms existing Triple-D and Quadruple-D scores in predicting ESWL failure, providing enhanced individualized risk stratification. This may facilitate better patient selection and treatment planning. Prospective validation is warranted.
Downloads
1. Qian X, Wan J, Xu J, et al. Epidemiological trends of urolithiasis at the global, regional, and national levels: a population-based study. Int J Clin Pract. 2022;2022:6807203. DOI: https://doi.org/10.1155/2022/6807203
2. Alhakamy M, AlShoaibi I, Abdo B, et al. Prevalence of urolithiasis in adults of the Eastern Mediterranean region: A systematic review and meta-analysis. Urol Sci. 2025:10.1097/us9.0000000000000076. DOI: https://doi.org/10.1097/us9.0000000000000076
3. Shafi H, Moazzami B, Pourghasem M, Kasaeian A. An overview of treatment options for urinary stones. Caspian J Intern Med. 2016;7:1-6.
4. Skolarikos A, Geraghty R, Somani B, et al. European Association of Urology guidelines on the diagnosis and treatment of urolithiasis. Eur Urol. 2025; 88:64-75. DOI: https://doi.org/10.1016/j.eururo.2025.08.023
5. Eslahi A, Ahmed F, Hosseini MM, et al. Minimal invasive percutaneous nephrolithotomy (Mini-PCNL) in children: Ultrasound versus fluoroscopic guidance. Arch Ital Urol Androl. 2021; 93:173-7. DOI: https://doi.org/10.4081/aiua.2021.2.173
6. Eslahi A, Ahmed F, Rahimi M, et al. Outcome of transperitoneal laparoscopic ureterolithotomy (TPLU) for proximal ureteral stone >15 mm: Our experience with 60 cases. Arch Ital Urol Androl. 2021;93:330-5. DOI: https://doi.org/10.4081/aiua.2021.3.330
7. Salah M, Al-Ghashmi M, Tallai B, et al. Predictors of treatment failure and outcome assessment of extracorporeal shock wave lithotripsy with the Dornier Compact Delta® III Pro: experience from the first 1000 treatments. Arch Ital Urol Androl. 2025; 97:13867. DOI: https://doi.org/10.4081/aiua.2025.13867
8. Petrides N, Ismail S, Anjum F, Sriprasad S. How to maximize the efficacy of shockwave lithotripsy. Turk J Urol. 2020; 46:S19-26. DOI: https://doi.org/10.5152/tud.2020.20441
9. Choi JW, Song PH, Kim HT. Predictive factors of the outcome of extracorporeal shockwave lithotripsy for ureteral stones. Korean J Urol. 2012; 53:424-30. DOI: https://doi.org/10.4111/kju.2012.53.6.424
10. Reynolds LF, Kroczak T, Pace KT. Indications and contraindications for shock wave lithotripsy and how to improve outcomes. Asian J Urol. 2018; 5:256-63. DOI: https://doi.org/10.1016/j.ajur.2018.08.006
11. Danuser H, Müller R, Descoeudres B, et al. Extracorporeal shock wave lithotripsy of lower calyx calculi: how much is treatment outcome influenced by the anatomy of the collecting system? Eur Urol. 2007; 52:539-46. DOI: https://doi.org/10.1016/j.eururo.2007.03.058
12. Augustin H. Prediction of stone-free rate after ESWL. Eur Urol. 2007; 52:318-20. DOI: https://doi.org/10.1016/j.eururo.2007.03.059
13. Al-Marhoon MS, Shareef O, Al-Habsi IS, et al. Extracorporeal shock-wave lithotripsy success rate and complications: initial experience at Sultan Qaboos University Hospital. Oman Med J. 2013; 28:255-9. DOI: https://doi.org/10.5001/omj.2013.72
14. Coskun A, Can U. Predicting stone-free status based on Quadruple-D and Triple-D scores after extracorporeal shock-wave lithotripsy and comparing with broad-spectrum population. Aktuelle Urol. 2024. DOI: https://doi.org/10.1055/a-2266-3564
15. Ipek OM, Dincer E, Sevinc AH, et al. Predictive performance of Triple-D, Quadruple-D, and Mayo adhesive probability scores in ESWL for renal stones: a retrospective cohort study. Urolithiasis. 2025; 53:96. DOI: https://doi.org/10.1007/s00240-025-01765-6
16. Ahmed F, Askarpour MR, Eslahi A, et al. The role of ultrasonography in detecting urinary tract calculi compared to CT scan. Res Rep Urol. 2018; 10:199-203. DOI: https://doi.org/10.2147/RRU.S178902
17. Vickers AJ, Elkin EB. Decision curve analysis: a novel method for evaluating prediction models. Med Decis Making. 2006; 26:565-74. DOI: https://doi.org/10.1177/0272989X06295361
18. Collins GS, Reitsma JB, Altman DG, Moons KGM. Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD): The TRIPOD statement. Eur Urol. 2015; 67:1142-51. DOI: https://doi.org/10.1016/j.eururo.2014.11.025
19. Tarawneh E, Awad Z, Hani A, et al. Factors affecting urinary calculi treatment by extracorporeal shock wave lithotripsy. Saudi J Kidney Dis Transpl. 2010; 21:660-5.
20. Yoon JH, Park S, Kim SC, et al. Outcomes of extracorporeal shock wave lithotripsy for ureteral stones according to ESWL intensity. Transl Androl Urol. 2021; 10:1588-95. DOI: https://doi.org/10.21037/tau-20-1397
21. Yin X, Li J, Pan C, et al. Development and validation of a predictive model for stone-free failure after extracorporeal shockwave lithotripsy in patients with ureteral stone in a large prospective cohort. World J Urol. 2023; 41:1431-6. DOI: https://doi.org/10.1007/s00345-023-04358-3
22. Satjakoesoemah AI, Alfarissi F, Wahyudi I, et al. Factors related to the success rate of pediatric extracorporeal shock wave lithotripsy (ESWL) in Cipto Mangunkusumo Hospital: an 8-year single-center experience. Afr J Urol. 2021;27:92. DOI: https://doi.org/10.1186/s12301-021-00187-1
23. Shinde S, Al Balushi Y, Hossny M, et al. Factors affecting the outcome of extracorporeal shockwave lithotripsy in urinary stone treatment. Oman Med J. 2018; 33:209-17. DOI: https://doi.org/10.5001/omj.2018.39
24. Çanakcı C, Dinçer E, Simsek B, et al. Effect of tissue densities at the skin-to-stone distance on the success of shockwave lithotripsy. J Urol Surg. 2024; 11:14-8. DOI: https://doi.org/10.4274/jus.galenos.2023.2023.0010
25. Sendogan F, Bulut M, Çanakçı C, et al. Quadruple-D score in the success rate of extracorporeal shock wave lithotripsy of renal stones in pediatric population. Urolithiasis. 2024; 52:163. DOI: https://doi.org/10.1007/s00240-024-01657-1
26. Caglar U, Halis A, Yazili HB, et al. The impact of Mayo Adhesion probability score on the success of extracorporeal shock wave lithotripsy for kidney stones. Urolithiasis. 2024; 53:8. DOI: https://doi.org/10.1007/s00240-024-01680-2
27. Elawady H, Mahmoud MA, Samir M. Can we successfully predict the outcome for extracorporeal shock wave lithotripsy (ESWL) for medium size renal stones? A single-center experience. Urologia. 2022; 89:235-9. DOI: https://doi.org/10.1177/03915603211016355
28. Oliveira B, Teixeira B, Magalhaes M, et al. Extracorporeal shock wave lithotripsy: retrospective study on possible predictors of treatment success and revisiting the role of non-contrast-enhanced computer tomography in kidney and ureteral stone disease. Urolithiasis. 2024; 52:65. DOI: https://doi.org/10.1007/s00240-024-01570-7
29. Vella M, Caramia M, Maltese M, et al. ESWL prediction of outcome and failure prevention. Urol Int. 2007; 79:S47-50. DOI: https://doi.org/10.1159/000104441
30. Anastasiadis A, Koudonas A, Langas G, Tsiakaras S, Memmos D, Mykoniatis I, et al. Transforming urinary stone disease management by artificial intelligence-based methods: A comprehensive review. Asian J Urol. 2023; 10:258-74. DOI: https://doi.org/10.1016/j.ajur.2023.02.002
How to Cite
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
PAGEPress has chosen to apply the Creative Commons Attribution NonCommercial 4.0 International License (CC BY-NC 4.0) to all manuscripts to be published.