Patient Preference for Management of an Asymptomatic 15 mm Renal Calculus-Avoid Risk or Maximize Success?

We evaluate patient preferences and the underlying factors determining decision making in the management of the asymptomatic 15 mm renal stone.

A survey was randomly distributed to 106 patients at our multidisciplinary stone clinic. Patients were given a hypothetical scenario of a 15 mm renal stone, and were asked to choose among the 3 treatment options of extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy. The success rate, risk and morbidity associated with each treatment were provided to patients. Statistical analysis involved the Fisher exact and Wilcoxon signed rank tests. Analysis was performed using standard computer software with p <0.05 considered statistically significant.

A total of 103 patients completed our survey, and 58 (56%) chose ureteroscopy, 26 (25%) chose percutaneous nephrolithotomy and 19 (19%) preferred shock wave lithotripsy as the treatment option. Patients who selected shock wave lithotripsy were increasingly concerned with risk rather than success rate (74% vs 16%, respectively). In contrast, patients who selected percutaneous nephrolithotomy were more concerned with the success rate rather than risk (81% vs 7.5%, respectively). Rates of success and risk were given approximately equal importance by patients selecting ureteroscopy (40% vs 48%, respectively).

Patients who choose percutaneous nephrolithotomy are primarily motivated by a desire to maximize success while the choice of shock wave lithotripsy is primarily motivated by a desire to minimize risks. The majority of patients selected ureteroscopy as a procedure with a balance of moderate risk and moderate success. Understanding the factors driving patient decision making would allow urologists to more effectively manage expectations and provide counseling.