Management patterns of medicare patients undergoing treatment for upper urinary tract calculi

Abstract

Purpose: We conducted this study to identify differences in the re-treatment rates and ancillary procedures for the two most commonly utilized stone treatment procedures in the Medicare population: ureteroscopy (URS) and shock wave lithotripsy (SWL).

Materials and methods: A retrospective claims analysis of the Medicare standard analytical file 5% sample was conducted to identify patients with a new diagnosis of urolithiasis undergoing treatment with URS or SWL from 2009-2010. Outcomes evaluated: (1) repeat stone removal procedures within 120 days post index procedure, (2) stent placement procedures on the index date, 30 days prior to and 120 days post index date, and (3) use of general anesthesia.

Results: We identified 3885 eligible patients, of which 2165 (56%) underwent SWL and 1720 (44%) underwent URS. Overall, SWL patients were 1.73 times more likely to undergo at least one repeat procedure than URS patients, and twice as likely to require multiple re-treatments compared to URS. Among those with ureteral stones, SWL patients were 2.27 times more likely to undergo repeat procedures. The difference was not statistically significant in renal stone patients. Overall, SWL patients were 1.41 times more likely than URS patients to have a stent placed prior to index procedure, and 1.33 times more likely to have a stent placed subsequent to the index procedure. The majority of URS patients (77.8%) had a stent placed at the time of index procedure. There was no significant difference in anesthetic approaches between SWL and URS.

Conclusions: Patients undergoing SWL are significantly more likely to require re-treatments than URS patients. SWL patients are also significantly more likely to require ureteral stent placement as a separate event. SWL and URS patients have similar rates of general anesthesia.