Speaker
Charles Scales, MD, MSHS
Associate Dean for Clinical Research Initiatives
Associate Professor, Urology and Population Health Sciences
Duke Clinical Research Institute
Keywords
Hydration; Urinary Stones; Behavioral Intervention; Behavioral Science; Urology
Key Points
- 10% of Americans will experience urinary stones (US) in their lifetime. Hydration is a mainstay of dietary US prevention, with guidelines recommending sufficient intake to produce 2500 mL of urine per day.
- The Prevention of Urinary Stones with Hydration (PUSH) trial team sought to test whether behavioral interventions to increase adherence to higher fluid intake prevented stone recurrence. The US incidence rate in the intervention group was slightly lower than that of the control group, but the difference was not statistically significant.
- PUSH was designed as a clinical trial with pragmatic features responsive to participant and coordinator feedback. Dr. Scales shared lessons learned around screening/baseline procedures, recruitment practices, leveraging data, and more. Next steps will include secondary analyses of 24-hour urine data and adolescents with urinary stone disease.
Discussion Themes
The trial’s negative result should not be interpreted as a failure of hydration to prevent kidney stones. It demonstrates, rather, that long-term adherence to hydration is difficult to maintain through behavioral nudges.
Dr. Scales recommended that future behavioral intervention trials consider SMART trial designs and incorporate patient preference assessments. He noted the importance of following patient-important outcomes.
Post-hoc analyses suggested a dose-response effect: Individuals who successfully increased their urine output by at least 0.5 liters had fewer stones.
The field should move toward tailoring hydration goals to an individual’s body habitus or activity level rather than a one-size-fits-all volume target.