Can a high-tech water bottle help reduce the recurrence of kidney stones? What about a financial incentive? Those are questions researchers funded by the National Institutes of Health will seek to answer as they begin recruiting participants for a two-year clinical trial at four sites across the country. Scientists will test whether using a smart water bottle that encourages people to drink more water, and therefore urinate, will reduce the recurrence of urinary stone disease, commonly referred to as kidney stones. The trial is supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of NIH.

The randomized trial, known as the Prevention of Urinary Stones with Hydration (link is external) study, or PUSH, will enroll 1,642 people, half in an intervention group and half in a control group. The study’s primary aim is to determine whether a program of financial incentives, receiving advice from a health coach, and using a smart water bottle will result in reduced risk of kidney stone recurrence over a two-year period. The water bottle, called Hidrate Spark, monitors fluid consumption and connects to an app.

Those in the intervention group will be asked to drink a specific quantity of fluids calculated based on each person’s urine output. They will also be given financial incentives if they achieve their fluid targets. They will also meet with a health coach who will help identify barriers to drinking more liquids, and help solve them. Study participants in both groups will receive the water bottles to monitor how much they drink and will be asked to try to achieve a goal of drinking enough to expel 2.5 liters of urine per day – about 10.5 cups.  

In the United States, the prevalence of urinary stones has nearly doubled in the past 15 years, affecting about 1 in 11 people. Little high-quality research exists related to how to prevent stones, and most therapies treat people with the condition only after they are in excruciating pain.

Existing prevention guidelines agree on one important lifestyle change: drinking more water. However, among people with a history of kidney stones — and who are routinely counseled to drink more water — the average increase in 24-hour urine volume is very small. PUSH researchers hope to identify ways to change and sustain behaviors that increase fluid intake and reduce urinary stone recurrence.

“Urinary stones are painful and debilitating, and their treatment expensive. We hope that identifying the barriers to water intake, and helping people overcome those barriers individually will be successful,” said Ziya Kirkali, MD, program director of urology clinical research and epidemiology in NIDDK’s Division of Kidney, Urologic, and Hematologic Diseases. “If successful, the study could change management of kidney stones, and could result in healthcare systems incorporating problem solving and prevention strategies, perhaps using incentives to modify behavior in people with urinary stone disease.”

PUSH participants must be 12 years of age or older, have had at least one symptomatic stone in the past three years, have a low urine amount (measured over 24 hours), own a smartphone, and meet other eligibility criteria, as outlined in the trials ClinicalTrials.gov page: NCT03244189, under grant DK110986.

PUSH is being conducted by investigators with the Urinary Stone Disease Research Network (USDRN). The Duke Clinical Research Institute is USDRN’s Scientific Data Research Center. PUSH will enroll at four clinical sites:

University of Pennsylvania/Children's Hospital of Philadelphia, University of Texas Southwestern Medical Center of Dallas, University of Washington, Seattle, Washington University in St. Louis

“Urinary stone disease remains an important medical, scientific, and public health problem, and it is an extraordinarily painful one for those it affects,” said NIDDK Director Dr. Griffin P. Rodgers, M.D., M.A.C.P. “With this trial, we’re leaning on technology to find a solution to preventing urinary stones that can fit into people’s lifestyles.”

The NIDDK, a component of the NIH, conducts and supports research on diabetes and other endocrine and metabolic diseases; digestive diseases, nutrition and obesity; and kidney, urologic and hematologic diseases. Spanning the full spectrum of medicine and afflicting people of all ages and ethnic groups, these diseases encompass some of the most common, severe and disabling conditions affecting Americans.