MedicalResearch: What are the main findings of the study?
Dr. Scales: When it comes to treating kidney stones, less invasive is not always better.
We used the best method short of a randomized trial to balance out patients in terms of factors that might influence the success of treatment. In other words, we achieved a “statistical toss-up” for factors that could influence the outcome of the procedure.
When we balanced out all of the factors that might influence the chance of a repeat procedure, we found that about 11% of patients treated with non-invasive SWL had a repeat procedure, as compared to <1% with minimally invasive URS.
MedicalResearch: Were any of the findings unexpected?
Dr. Scales: We were surprised at the magnitude of the difference in effectiveness of the two treatments. These findings are important because repeat treatments can be costly in terms of patient time and costs to the health care system.
MedicalResearch: What should clinicians and patients take away from your report?
Dr. Scales: Patients should know that important tradeoffs exist when selecting a treatment to remove a kidney stone, even among first-line procedures. For example, it might be easier to get access to a shock wave treatment because the devices can travel from hospital to hospital on a truck, but patients might have to travel farther to get a ureteroscopy – but the risk of needing another treatment is higher. Non-invasive does not automatically mean better.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. Scales: Three important areas for future research are highlighted by our findings.
First, we need to understand how to explicitly incorporate patient preferences into treatment decision-making.
Second, these findings highlight the need for further engineering research to improve the efficacy of shock wave devices.
Finally, we need to understand the implications of these findings for the costs of treating patients with kidney stones, since the less effective procedure is reimbursed at a higher rate.