Kidney stones affect an estimated 8.8% of American adults and direct medical costs exceed $10 billion annually. Five-year recurrence rates for stones have been as high as 40% and a standard guideline for prevention is to increase fluid intake enough to produce > 2.5 L of urine daily. Meeting these guidelines reduces stone recurrence rates by 50-60% yet patients’ adherence to fluid intake guidelines is commonly below 50%. Usual care for preventing a recurrence involves education about increasing fluid intake and dietary changes; however, the low adherence rate indicates that many patients would benefit from additional support in adhering to fluid intake guidelines. The long-term goal of this research is to reduce the recurrence of painful and costly stones by improving patient adherence to fluid intake guidelines (secondary prevention). Digital technology offers the promise of increasing reach and supporting treatment adherence but, to date, that promise has not been fully realized in clinical trials of digital tools for supporting treatment adherence. In a series of six preliminary studies, we engaged patients in developing and testing a context-sensitive digital tool called sipIT, a just-in-time adaptive intervention to promote fluid intake and increase urine output. We learned that patients are open to using digital tools provided those tools are integrated with their lifestyle and sensitive to the changing contexts of their lives. The resulting intervention, sipIT, incorporates a novel semi-automated tracking system to trigger smartphone notifications with context-sensitive reminders to drink. The reminder system was informed by contemporary theories of habit formation to support behavior change in the eventual absence of the technology. In this application, we propose to answer question, “Does sipIT increase 24-hour urine output more than usual care over a 3-month period?” Urine output was selected as a proximal surrogate endpoint based on clinical guidelines for preventing recurrence of kidney stones. The specific aims of this project are (1) to evaluate the efficacy of sipIT vs usual care for increasing urine output in patients with a history of kidney stones, and (2) to identify biological and behavioral moderators of intervention effects on urine output (heterogeneity of treatment effects). We propose a two-arm randomized controlled trial to achieve these aims. Patients will receive either usual care + sipIT (intervention group) or usual care alone (control group). We will evaluate 24-hour urine output, urine supersaturations, and fluid intake habit strength at baseline and 1, 3, and 12 months after intervention. If successful, this research will lead to a cost-effective intervention that leverages consumer technology so it can be scaled for dissemination and implementation in clinical practice to reduce the burden and cost of stones. It advances NIDDK goals of preventing noncancerous urologic diseases and may be applied to support other dehydration-related health concerns (e.g., urinary tract infections, cognitive performance, heat stress, post-surgical hospital readmissions).
The preliminary studies leading to the grant described above were supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant UL1 TR002014. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.