Change of Trends in the Treatment Modality for Pediatric Nephrolithiasis: Retrospective Analysis of a US-Based Insurance Claims Database.

Purpose: The objective of this study was to show the prevalence and investigate treatment trends of pediatric nephrolithiasis based on a large population of U.S. insurance individual's data. Materials and Methods: This research involved a retrospective observational cohort study. Administrative claims data were extracted from the IBM® MarketScan® Research Database. We included all patients newly diagnosed with nephrolithiasis, aged <18 years old at the time of diagnosis from January 1, 2007, to December 31, 2014. The patient cohort with nephrolithiasis was selected using the International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) code for nephrolithiasis. Each treatment method was searched by Current Procedural Terminology (CPT) code. Results: A total of 28,014 patients were found to have nephrolithiasis in our cohort. Of nephrolithiasis patients, 701 (2.5%) patients were treated by surgical methods. The mean age of patients at the time of treatment was 13 years old. Extracorporeal shockwave lithotripsy (SWL) was the most used treatment modality during the period. SWL was performed in 66% of patients. The number of cases of SWL did not tend to change according to year, whereas retrograde intrarenal surgery (RIRS) tended to increase from 15% to 31%. Percutaneous nephrolithotripsy (PCNL) decreased from 13% to <10 cases. The number of open surgeries was very small and did not show any tendency. Conclusion: During the study period, SWL is stable. RIRS has become more popular in treating renal stones, whereas PCNL has decreased. These results suggest that the RIRS has become more popular than PCNL in treating large renal stones.