Renal calculi: Trends in the utilization of shockwave lithotripsy and ureteroscopy

Introduction: To assess trends in the usage of extracorporeal shockwave lithotripsy (SWL) and ureteroscopy (URS) in the treatment of renal calculi. Materials and methods: An analysis of the 5% Medicare Public Use Files (years 2001, 2004, 2007 and 2010) was performed to evaluate changes in the use of SWL and URS to treat renal calculi. Patients were identified using ICD-9 (cm) and CPT codes. Statistical analyses, including the Fisher, χ² tests, and multivariate logistic regression analysis were performed using SAS 9.3 (SAS Institute Inc., Cary, NC, USA) and SPSS υ20 (IBM Corp., Armonk, NY, USA). Results: The absolute number of patients diagnosed with (+85.1%) and treated for (+31.5%) kidney calculi increased from 2001 to 2010. The ratio of diagnosed/treated patients declined from 15.2% in 2001 to 10.8% in 2010. Whites (OR = 1.27, p < 0.0001), patients in the South (OR = 1.16, p < 0.0001) and those ≤ 84 years of age were more likely to be treated. The utilization of SWL (84.7%) was greater than URS (15.3%), but the utilization of URS increased over time from 8.4% in 2001 to 20.6% of cases by 2010 (p < 0.0001). Treatment via URS was more likely in women (OR = 1.28, p < 0.0001), in patients living outside the South (OR = 1.29-1.45, p ≤ 0.006) and in later years of the study (OR = 2.87, p < 0.0001). Conclusions: Treatment patterns for renal calculi changed from 2001 to 2010. The usage of URS increased at the cost of SWL. Multiple sociodemographic factors correlated with the likelihood of being treated surgically as well as the choice of the surgical approach.