With the prevalence of urinary stone disease (USD) nearly doubling over the last 15 years, there has been a concomitant rise in the impact it has on our healthcare system. Stones now affect 1 in 11 people in the United States and hydration and increasing urinary output (UOP) has long been shown to be a successful and cost-effective method in reducing their recurrence. However, maintaining adequate fluid intake to maximize patient benefit has been a long-standing barrier. A new 2-year clinical trial that focuses on behavioral adaptation in patients, called The Prevention of Urinary Stones with Hydration (PUSH), is being conducted as part of an initiative by the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK). Its goal is to determine whether using a high-tech water bottle alongside an app (in addition to financial incentives) can help with patient behavior modification to increase fluid intake.

The PUSH protocol was recently published in AJKD and is a 2-arm, multicenter, randomized controlled clinical trial that will enroll 1,642 subjects, half in an intervention group and half in a control group. The study’s primary endpoint will assess the recurrence rate of stones over the course of 24 months, whereas secondary endpoints include changes in radiographic stone burden, changes in 24-hour UOP, and changes in urinary symptoms. Both the intervention group and control group receiving financial incentives, while the intervention group also receive personalized coaching to help overcome individual barriers to increasing fluid intake. Additionally, they will be given a “fluid prescription” which will be modified as needed, based on the 24-hour UOP. Fluid intake will be monitored via a smart water bottle called “Hidrate Spark,” which can monitor fluid intake and automatically uploads data via an app.

Figure 1 from Scales et al, AJKD © National Kidney Foundation

Participants in the intervention arm who are unsuccessful in increasing their fluid intake based solely on financial incentives are then given “structured problem solving”. This initiative consists of a health coach helping to identify key barriers (ie, access to water, limited bathroom access, participants underestimating the chance of recurrent stones and overactive bladders) in participants’ lives to help increase fluid intake. Overall, the intervention arm of the trial is divided into four 6-month phases: Induction, Consolidation, Tapering, and Maintenance. It is hypothesized that using this adaptable behavioral intervention (which includes the structured problem solving) may help nurture new habits and sustainable lifestyle modifications that can last even after the trial is complete.

There are however, some potential limitations, duly recognized by the authors. For instance, incorporation of a 24-hour urine volume as a secondary outcome may not be reflective of daily urine volume if participants purposely increase fluid intake only during the 24-hour collection period.  Similarly, the study relies on participants utilizing the smart bottle to measure all fluid intake, which can have some human error associated with it.

Graphical Abstract from Scales et al, AJKD © National Kidney Foundation

The PUSH trial looks to utilize a multimodel behavioral intervention that focuses not just on the medical aspect, but personalized social barriers as well, to increase adherence to fluid intake as a means to prevent recurrent USD. If successful, this trial could serve as a pilot for interventional behavior modifications for other disease conditions including weight loss and smoking cessation, among many more.

– Post prepared by Shubha Mathur (AJKDBlog Guest Contributor) and Edgar V. Lerma @edgarvlermamd, AJKD Social Media Advisory Board member. 

To view Scales et al, please visit AJKD.org.

Title: Prevention of Urinary Stones With Hydration (PUSH): Design and Rationale of a Clinical Trial
Authors: Charles D. Scales Jr., Alana C. Desai, Jonathan D. Harper, H. Henry Lai, Naim M. Maalouf, Peter P. Reese, Gregory E. Tasian, Hussein R. Al-Khalidi, Ziya Kirkali, Hunter Wessells on behalf of the Urinary Stone Disease Research Network
DOI: 10.1053/j.ajkd.2020.09.016