Initial results from the M-STONE group: A Multi-center collaboration to Study Treatment Outcomes in Nephrolithiasis Evaluation.

Despite proven effectiveness of medications in preventing stone recurrence, compliance with pharmacotherapy is often poor due to cost, side effects and impact on lifestyle. We sought to compare the risk of stone recurrence between patients managed with conservative therapy versus pharmacotherapy controlling for aggressiveness of stone disease.

The Multi-center collaboration to Study Treatment Outcomes in Nephrolithiasis Evaluation (MSTONE) database contains patient data and outcomes from July 2001 to April 2015 across four centers. The database was queried for patients whose stone disease was managed with conservative therapy alone (CT, fluid and dietary recommendations) versus pharmacotherapy (PT). Patients were risk stratified according to number of previous passed stones. Within each risk group, we compared CT versus PT with respect to 2-year stone event rate and stone event-free survival (SEFS) via the Kaplan-Meier method.

A total of 245 patients, with a median follow-up of 29 months (IQR 16 - 44), were identified, including 93 on CT and 152 on PT. The overall 2-year stone-event rate was 38% for all patients. Stone events at 2 years occurred less frequently in the PT group compared to the CT group (31% vs 44%, p = 0.043), with the difference most pronounced in the high risk group (71% versus 32% for CT and PT, respectively, p = 0.058). The 30-month SEFS was significantly higher for PT (58%) than CT (46%) overall. When stratified by risk group, 30-month SEFS was statistically significantly higher for PT than CT in the intermediate risk group (65% vs 45% for PT and CT, respectively).

Controlling for aggressiveness of stone disease, PT was more effective than CT in reducing and delaying stone-related events. However, CT appeared to be as effective as PT in low risk patients. PT is best reserved for recurrent stone formers, regardless of metabolic background.

Journal of endourology. 2020 Jul 13 [Epub ahead of print]

Brett Allen Johnson, Sara L Best, Stephen Y Nakada, Chad Robert Tracy, Ryan L Steinberg, Lewis Thomas, Tracy Marien, Nicole Miller, Elly Kolitz, Adam Cohen, Margaret S Pearle, Yair Lotan, Jodi A Antonelli

University of Texas Southwestern, Urology, 5323 Harry Hines Blvd. MC 9110, Dallas, Texas, United States, 75214; ., University of Wisconsin School of Medicine and Public Health, Urology, 1685 Highland Ave, MFCB-3229, Madison, Wisconsin, United States, 53705., University of Wisconsin-Madison School of Medicine and Public Health, 5232, Urology, Madison, Wisconsin, United States; ., University of Iowa, Urology, 200 Hawkins Dr., 3 RCP, Iowa City, Iowa, United States, 52242-1089; ., UT Southwestern, Urology, 2001 Inwood Road, Building WCB3, Suite 4.886, Dallas, Texas, United States, 75390-9110; ., University of Iowa, Urology, Iowa City, Iowa, United States; ., NYU Medical Center, Urology, 150 east 32nd st, New York, New York, United States, 10016; ., Vanderbilt University Medical Center, 12328, Urology, A-1302 MCN, Nashville, Tennessee, United States, 37232; ., UT Southwestern Medical Center, Urology, Dallas, Texas, United States; ., UT Southwestern Medical Center, Urology, Dallas, Texas, United States; ., UT Southwestern Medical Center, Urology, 5323 Harry Hines Blvd, J8.106, Dallas, Texas, United States, 75390-9110; ., University of Texas Southwestern Medical Center, Department of Urology, 5323 Harry Hines Blvd. J8.112, Dallas, Texas, United States, 75390; ., UT Southwestern Medical Center, Urology, 5323 Harry Hines Blvd J8.106, Dallas, Texas, United States, 75390-9110; .