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).
Dual-process mechanisms of action for sipIT intervention effects in patients with urolithiasis
Secondary prevention of kidney stones is a major challenge for patients with urolithiasis. Increasing fluid intake to produce a urine output greater than 2.5 L/day is at the core of prevention guidelines from the American Urological Association. Patients are widely aware of the guidelines; however, less than 50% of patients adhere to those guidelines commonly due to lack of thirst or forgetting to drink. Usual care involves educating patients about increasing fluid intake, dietary modification, as well as periodically evaluating 24-hour urine volumes and other risk factors; but despite this practice, 10-year recurrence rates can still be as high as 80%. Our team developed sipIT, a behavioral intervention that leverages digital tools to provide just-in-time support for fluid intake in patients with urolithiasis. The Parent R01 (DK124469) will answer the question, “Does sipIT increase 24-hour urine volume more than usual care over a 3-month period?” In this application, we propose to examine how and why this intervention works over time by answering the question, “How do the reflective and automatic behavioral processes engaged by sipIT change during and after a 3-month intervention period to influence changes in urine output?” Answers to this question may help to inform clinicians how to counsel patients to best use digital tools over time, especially during stressful life events as patients may be more susceptible to symptomatic kidney stones. This application responds to NOT-OD-23-083 (Elucidate Fundamental Processes Underlying Behavior Change, Maintenance & Adherence). The specific aims of this project are (1) to determine how the timing and amount of change in reflective and automatic motivational processes are associated with increases 24-hour urine volume, and (2) to elucidate the correlates and consequences of fluid intake habit decay following the 3-month sipIT intervention period. To achieve these aims, we propose a 24-week ambulatory monitoring study that fuses user data from a mobile app for manually tracking fluid intake with weekly self-reports during a 12-week intervention period and monthly reports during a 12-week post-intervention period. Patients with a history of kidney stones will receive the sipIT intervention for 12 weeks. We will evaluate 24-hour urine output at baseline, 12 weeks (end of intervention), and 24 weeks (maintenance). Urine output was selected as the indicator of fluid intake based on clinical guidelines for preventing recurrence of kidney stones. Findings from this project will inform decisions about how long patients should use sipIT to develop long-term habits that will maintain non-thirst driven fluid intake. Results will also illuminate the robustness of formed habits to decay following the withdrawal of (negative) reinforcement for meeting hourly fluid intake goals. These insights into the reflective and automatic mechanisms of action of sipIT will lead to a more efficient intervention that meets patients’ needs for effective long-term behavior change. Insights into how and why the sipIT intervention works will advance NIDDK goals of preventing noncancerous urologic diseases and OBSSR goals of improving synergy between basic and applied behavioral and social science research.
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.