Clinical and cost-effectiveness of percutaneous nephrolithotomy, flexible ureterorenoscopy and extracorporeal shockwave lithotripsy for lower pole stones: the PUrE RCTs.

Background: Renal tract stone disease is common. The three intervention options are shockwave lithotripsy, flexible ureteroscopic stone treatment and keyhole surgery. Objectives: To determine which of shockwave lithotripsy, flexible ureteroscopic stone treatment and keyhole surgery offer the best outcomes in terms of health and quality of life, clinical effectiveness and cost-effectiveness for people with lower pole kidney stones. Design: The PUrE study comprised two pragmatic multicentre, open-label, superiority randomised controlled trials: RCT1 for lower pole stones ≤ 10 mm and RCT2 for lower pole stones > 10 and ≤ 25 mm. Setting: National Health Service Urology departments. Participants: Adults presenting with lower pole renal stones, able to undergo any of the treatments and complete trial procedures. Intervention: Eligible participants were randomised in RCT1 to flexible ureteroscopic stone treatment or shockwave lithotripsy; and in RCT2 to flexible ureteroscopic stone treatment or keyhole surgery. Main outcome measures: The primary outcome measure was health status 'area under the curve', measured weekly to 12 weeks post intervention with the EuroQol-5 Dimensions, five-level version. The primary economic outcome was the incremental cost per quality-adjusted life-year gained at 12 months from randomisation. Results: Primary outcome: Economic evaluation: Limitations: Blinding of participants and healthcare providers was not possible. There were differential waiting times between interventions in RCT1; however, adjusting for this gave similar treatment effect estimates. Conclusions: The PUrE study found in RCT1 that shockwave lithotripsy was more cost-effective than flexible ureteroscopic stone treatment, with no meaningful difference in patient health status even though complete stone-free rates were higher with flexible ureteroscopic stone treatment. In RCT2, keyhole surgery was more cost-effective than flexible ureteroscopic stone treatment on a micro-costing basis, which better reflects treatment cost differences to the NHS. Keyhole surgery was marginally beneficial for health status with higher complete stone-free rates. Future work: What effect will suction devices, improvements in laser technology, and intraoperative pressure monitoring have on postoperative pain, quality of life, stone-free rates, complications, and costs of flexible ureteroscopic stone treatment? What effect does miniaturisation of keyhole surgery have on postoperative pain, length of stay, complications, stone-free rates and costs? Trial registration: This trial is registered as ISRCTN98970319. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 13/152/02) and is published in full in