Presentation Authors: Jonathan Suderman*, Shubha De, Joe Labossiere, Trevor Schuler, Edmonton, Canada, Tim Wollin, Edmonotn, Canada
Introduction: Treatment options for renal calculi are well established for smaller stones ( < 10mm), and larger stones (>20mm). Smaller stones are often treated with surveillance, shockwave lithotripsy, or flexible ureteroscopy (URS) while calculi larger than 20 mm are typically treated with percutaneous nephrolithotripsy (PCNL). Treatment guidelines for renal calculi in the transition zone with stone sizes that approach 20 mm are not as well defined. The objective of this study was to compare ureteroscopic laser lithotripsy to PCNL for the treatment of renal calculi measuring 15-20 mm and to determine which of these two would be the preferred treatment considering cost and patient preferences (utilities).
Methods: The cost and utilities of URS and PCNL were compared for the treatment of 15-20 mm renal calculi using a cost-utility decision analysis model. Probability estimates were derived from the literature. Direct third-party payer costs were determined in Canadian dollars and obtained from Data Integration and Management Repository (DIMR) of Alberta Health Services and the Schedule of Medical Benefits, Alberta Health and Wellness. There is a paucity of previously reported measured health utilities for the treatment of nephrolithiasis, therefore, preferences were measured by proxy via an expert panel using the validated EQ-5D health status instrument. The decision analysis model was created and then run using TreeAge Pro software.
Results: The model predicted URS and laser lithotripsy ($6356 per patient with utility = 0.75) to dominate PCNL ($10,244 per patient with utility = 0.77) with a cost/utility ratio of $8475 for URS compared $13,304 for PCNL. This yields an incremental cost-savings of $4829 per patient favoring the URS strategy. The validity of the model was tested with sensitivity analysis.
Conclusions: From an economic perspective, this model predicts that ureteroscopic laser lithotripsy should be used over PCNL for the treatment of most renal calculi measuring 15-20 mm. However, the model also predicts that overall patient preference/utility is similar for both treatments with PCNL having a slightly better estimated patient preference.