Kidney stones are solid deposits that develop in the kidneys when there is a high concentration of certain minerals and salts in the urine. Kidney stones vary in size, shape and type, and can cause severe pain when leaving the body. Kidney stones are more common in men than women and individuals who have had a kidney stone in the past are more likely to have another. Although there are several factors associated with the development of kidney stones, one of the main risk factors is inadequate hydration. Prevention of Urinary Stones with Hydration (PUSH) is a randomized clinical trial that will try to determine whether kidney stone recurrence can be prevented or reduced by increased fluid intake and urine output.

PUSH participants will be randomized into two groups and given a “smart” water bottle to measure their fluid consumption. The control group will receive standard guideline-based recommendations to increase their overall fluid intake in order to achieve the study-specified urine output. The experimental group will be provided individualized “fluid prescriptions”, indicating the additional daily fluid amount the participant needs to consume, as well as a behavioral program consisting of financial incentives and structured problem solving. During the 24-month study period, participants will be monitored for the formation and passage of any kidney stones via periodic 24-hour urine collections, CT scan or ultrasound imaging, and follow-up questionnaires.

The objective of the PUSH study is to evaluate how kidney stone recurrence is affected by increased fluid consumption and urine output.

Primary Outcome Measures: The time from Baseline to the passage or removal of a stone will be measured and compared between the two groups.

Secondary Outcome Measures: Imaging will be used to assess asymptomatic stone formation, stone recurrence, and the increase in size of any existing stones. The presence of lower urinary tract symptoms, 24-hour urine output, and the costs of study interventions and treatments during the follow-up period will also be evaluated.

Inclusion Criteria: Participants of this study must be age 12 or older; have had at least one symptomatic stone event within the past 3-5 years prior to enrollment; have low 24-hour urine volume; own and use a smartphone or other device compatible with the “smart” bottle.

Exclusion Criteria: Individuals will be excluded from this study if they have a spinal cord injury; a history of cancer or currently undergoing active treatment for cancer (except basal cell skin cancer); diagnosed infectious, monogenic, or other causes of stone disease where the course of the disease could be likely to significantly altered by therapies; current or previous hyponatremia or hypo‐osmolality; surgeries or comorbidities that prohibit high fluid intake or lead to GI fluid losses; women who are currently pregnant or plan to become pregnant within the next 2 years; recipient of a renal transplant; bedridden; uncorrected anatomical obstruction of the urinary tract or anatomical urologic abnormalities (ileal conduits, solitary kidney, etc.); history of recurrent urinary tract infections; chronic use of lithium; long-term glucocorticoid use; daily intake of narcotic medication for more than 30 prior to enrollment; daily intake of more than one gram of supplemental vitamin C; have developed stones after the initiation of medications that are strongly associated with urinary stone disease (USD) and have discontinued or plan to discontinue these medications; have stones that are composed of medications that may crystallize in the urine and have discontinued or plan to discontinue these medications; have a life expectancy that is less than two years; are non-English speakers; have a history of SIADH; psychiatric conditions that will impair study compliance; a part of a vulnerable population; or the investigator determines that the individual will be unable to participate in the protocol.

The study is ongoing