Introduction: Guidelines for the treatment of renal stones 1-2cm in size include ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), and extracorporeal shock wave lithotripsy (ESWL). A recent meta-analysis comparing these treatments found the highest stone-free rate with PCNL, followed by URS and ESWL; however, complication rates were highest for PCNL. A cost-effectiveness evaluation comparing these three modalities has not yet been performed.
Methods: A Markov decision analytic model was created to compare cost-effectiveness of PCNL, URS, and ESWL for 1-2cm renal stones based on stone free and complication rates from a meta-analysis. Costs were based on 2018 Medicare rates. Quality adjusted life years (QALYs) were assigned from the literature. The incremental cost-effectiveness ratio (ICER) between strategies was compared, using a willingness-to-pay (WTP) threshold of $100,000/QALY. Univariate and multivariable Monte Carlo sensitivity analyses were performed. A subset analysis was performed for 1-2cm lower pole stones.
Results: At 3 years follow up, mean costs per patient were $10,079 (PCNL), $5,779 (URS), and $4,804 (ESWL). PCNL resulted in the highest QALYs at 2.97 compared to 2.96 and 2.95 for URS and ESWL, respectively. On aggregate, PCNL was not cost-effective relative to ESWL ($302,751/QALY) or URS ($1,466,110/QALY), whereas URS was more cost-effective than ESWL (ICER=$67,257/QALY). The model was sensitive to the stone free rate of ESWL and URS as well as the cost of PCNL, URS, and ESWL. ESWL became most cost-effective with a stone free rate =69% or URS stone free rate =82%. PCNL became most cost-effective when cost =$5,205. On multivariable sensitivity analysis, the most cost-effective strategy was URS in 67%, ESWL in 32.5%, and PCNL in 0.5% of simulations. When evaluating lower pole stones alone, the most cost-effective strategy was URS in 84%, ESWL in 8%, and PCNL in 8% of microsimulations (Figure).
Conclusions: For 1-2 cm stones, URS is most likely to be cost-effective on a population level based on data from meta-analyses. However, for lower pole stones, particularly with a higher willingness to pay threshold, PCNL becomes increasingly favorable. Source of