Prevention of Urinary Stones With Hydration (PUSH)
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ClinicalTrials.gov Identifier: NCT03244189 |
Recruitment Status :
Active, not recruiting
First Posted : August 9, 2017
Last Update Posted : February 28, 2022
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Condition or disease | Intervention/treatment | Phase |
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Urinary Stones | Behavioral: Fluid prescription Behavioral: Financial incentive Behavioral: Structured Problem Solving | Not Applicable |
This is a two arm randomized controlled trial that incorporates pragmatic features, an adaptable intervention, patient choice, and remote monitoring of fluid intake through a "smart" water bottle. The study period is 24 months and will enroll approximately 1642 participants. Randomization will be stratified within a study site by age (adult vs. adolescent) and first time vs. recurrent stone former.
Intervention and control arm study participants will receive a smart water bottle that records daily fluid consumption, usual care including guideline-based recommendations of adequate fluid intake to decrease kidney stone recurrence, and periodic 24 hour urine collections, imaging (low-dose CT scan or ultrasound) and follow-up questionnaires.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 1658 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Single (Investigator) |
Masking Description: | The Principal Investigator and site investigators, along with the primary study statistician will remind blinded throughout the trial. |
Primary Purpose: | Prevention |
Official Title: | Prevention of Urinary Stones With Hydration |
Actual Study Start Date : | October 4, 2017 |
Estimated Primary Completion Date : | February 29, 2024 |
Estimated Study Completion Date : | February 29, 2024 |

Arm | Intervention/treatment |
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Experimental: Intervention
Participants in the intervention arm will receive an individualized "fluid prescription", which will be the additional volume of fluid intake needed to maintain a study-specified urine output. This fluid will be consumed from and measured by a smart water bottle. The intervention arm also includes a behavioral program that consists of financial incentives and structured problem solving (SPS) to maintain the recommended fluid intake.
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Behavioral: Fluid prescription
The additional amount of fluid that the participant will need to consume each day, using the smart water bottle, in order to meet the study-specified urine output. This fluid is in addition to any other sources of fluid (ex. cups of coffee, bottled sports drink) that the participant consumes each day. Behavioral: Financial incentive Participants in the Intervention Arm who meet their fluid intake goal on randomly selected days will receive a small payment for that day. Behavioral: Structured Problem Solving Structure Problem Solving involves interactions with health coaches to help participants develop feasible solutions to overcoming personal barriers to maintaining the prescribed fluid intake. |
No Intervention: Control
Participants in the control arm will receive standard care instructions according to American Urological Association (AUA) guidelines to increase overall fluid consumption to achieve study-specified urine output. They will also receive a "smart" water bottle with capability to self-monitor their fluid intake.
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- Stone passage observed and/or captured by the study participant. [ Time Frame: From Baseline through 24 months. ]Will be measured by the time from Baseline to the passage of 1 or more stones by a participant.
- Procedural intervention for symptomatic stone [ Time Frame: From Baseline through 24 months. ]From Baseline through 24 months; will be measured by the time from Baseline to a procedure to remove a symptomatic stone by a participant.
- Any procedural intervention for removal of asymptomatic renal or ureteral stone [ Time Frame: From Baseline through 24 months. ]Will be measured by the time from Baseline to a procedure to remove an asymptomatic stone by a participant.
- Asymptomatic formation of new stone detected by imaging [ Time Frame: From Baseline through 24 months. ]Will be measured by the time from Baseline to the formation of an asymptomatic stone by a participant.
- Change in size of existing stone by ≥ 2 mm in any dimension detected by imaging [ Time Frame: From Baseline through 24 months. ]Comparison of the size of any stone on first observation versus later observations or at passage. Will be measured primarily through imaging (CT scan or ultrasound).
- Composite outcome: symptomatic stone recurrence, asymptomatic stone formation, increase of existing stone by ≥2 mm in any dimension detected by imaging [ Time Frame: From Baseline through 24 months. ]
- 24 hour urine total volume [ Time Frame: From Baseline through 24 months. ]Will measure and compare 24 hour urine volumes from screening through 24 months.
- Costs of study interventions and treatments for USD during the follow-up period [ Time Frame: Compared total between Baseline and the Month 24 visit. ]
- Presence of lower urinary tract symptoms (Comprehensive Assessment of Self-reported Urinary Symptoms) [ Time Frame: From Baseline through the Month 24 visit. ]Will compare the results of the CASUS questionnaires completed throughout the study

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 12 Years and older (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Aged ≥ 12 years
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At least 1 symptomatic stone event (passage or procedural intervention) within 3 years prior to enrollment or a symptomatic stone event within 5 years if the patient also has new stone formation detected on imaging during the last 5 years. Symptomatic stone defined as any of the following:
- Stone passage
- Procedural intervention
- Radiographically or ultrasonographically confirmed stone with any of the following:
i. Gross hematuria ii. Renal colic or atypical abdominal pain attributed to the stone, as determined by a treating provider iii. A clinical pattern of intermittent symptoms consistent with intermittent obstruction at the ureteropelvic junction, as determined by a treating provider
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Low 24-hr urine volume
- ≥18 years old: <2.0 L/day
- <18 years old: <25 ml/Kg/day up to 2.0L/day
- Able to provide informed consent (parental permission for children)
- Owning and willing to use a smartphone or other device (e.g., tablet) compatible with the study-provided wireless enabled "smart" bottle
Exclusion Criteria:
- Spinal cord injury
- Currently undergoing active treatment for cancer except basal cell skin cancer, or patients with a history of cancer who completed their initial therapy <1 year before screening.
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Known infectious (struvite), monogenic or other causes of stone disease for which therapies are likely to significantly alter course of stone disease
- Cystinuria
- Primary hyperoxaluria
- Primary xanthinuria
- Primary hyperparathyroidism
- Sarcoidosis
- Medullary sponge kidney
- History or presence of hyponatremia (serum sodium <130 mmol/L) or hypo-osmolality (serum osmolality <275 mosm/kg)
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Study participants with comorbidities that preclude high fluid intake or prior surgery precluding high fluid intake or leading to GI fluid losses
- History of or current Crohn's disease, ulcerative colitis, short gut syndrome (e.g. ileostomy, bowel bypass surgery to treat obesity, small bowel resection), chronic diarrhea, or GI tract ostomy.
- History of malabsorptive (e.g., Roux-en-Y gastric bypass) or restrictive (e.g., sleeve gastrectomy) bariatric surgery procedures
- Congestive heart failure
i. NYHA class II or greater, and/or ii. Hospital admission in the past year for heart failure d. Lung disease with a home oxygen requirement e. Chronic kidney disease (eGFR <30 ml/min/1.7 m2 over a 3-month period) i. For adults (age ≥18), we will use the CKD-Epi equation which requires the measurement of serum creatinine only. ii. For children (age <18), we will use the bedside Schwartz (CKiD) formula. f. Nephrotic syndrome (>3.5 grams of protein per 24 hours) g. Cirrhosis with ascites
- Women who are currently pregnant or planning pregnancy within 2 years.
- Renal transplant recipient
- Bedridden study participants (ECOG ≥ 3)
- Uncorrected anatomical obstruction of the urinary tract
- History of recurrent urinary tract infections (> 3 UTI/year proven by urine culture)
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Exclusions due to medication use:
- Chronic use of lithium
- Long-term glucocorticoid use (> 7.5 mg prednisone daily for > 30 days prior to enrollment)
- Intake of narcotic medication on a daily basis for >30 days prior to enrollment
- Supplemental Vitamin C (> 1 g daily)
- Individuals with stones that have developed after the initiation of medications that are strongly associated with USD such as carbonic anhydrase inhibitors (acetazolamide, topiramate, zonisamide), high dose vitamin C (> 1 g daily), high dose calcium supplementation (> 1,200 mg daily) AND who have discontinued or plan to discontinue these medications.
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Individuals with stones composed of medications that may crystallize in the urine (guaifenesin, sulfonamides, triamterene, and the protease inhibitors indinavir and nelfinavir) AND who have discontinued or plan to discontinue these medications.
Note: Individuals who are on long-term medications that increase the risk of stone disease, who cannot stop these medications due to other chronic conditions (e.g., HIV) and who may reduce their risk for stone recurrence through increased fluid intake, will be eligible to participate in the trial. Examples of these medications include:
- Carbonic anhydrase inhibitors (acetazolamide, topiramate, zonisamide)
- Medications that may crystallize in the urine (guaifenesin, sulfonamides, triamterene, and the protease inhibitors indinavir and nelfinavir).
- Study participants <2 yrs life expectancy
- Non-English Speakers
- History of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)
- Anatomical urologic abnormalities including ileal conduits, horseshoe kidney, megaureter or solitary kidney.
- Psychiatric conditions impairing compliance with the study
- Vulnerable population (prisoner and/or cognitive impairment that the investigator feels will impact the study participant's ability to participate in the protocol)
- Individual who will be unable to participate in the protocol in the judgment of the investigator.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03244189
United States, Minnesota | |
Mayo Clinic | |
Rochester, Minnesota, United States, 55905 | |
United States, Missouri | |
Washington University, St. Louis | |
Saint Louis, Missouri, United States, 63110 | |
United States, Ohio | |
Cleveland Clinic | |
Cleveland, Ohio, United States, 44195 | |
United States, Pennsylvania | |
University of Pennsylvania | |
Philadelphia, Pennsylvania, United States, 19104 | |
Children's Hospital of Philadelphia | |
Philadelphia, Pennsylvania, United States, 19146 | |
United States, Texas | |
Children's Hospital | |
Dallas, Texas, United States, 75390 | |
University of Texas Southwestern | |
Dallas, Texas, United States, 75390 | |
United States, Washington | |
University of Washington | |
Seattle, Washington, United States, 98195 |
Principal Investigator: | Charles Scales, MD, MSHS | Duke University |
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Duke University |
ClinicalTrials.gov Identifier: | NCT03244189 |
Other Study ID Numbers: |
Pro00083271 1U01DK110988 ( U.S. NIH Grant/Contract ) |
First Posted: | August 9, 2017 Key Record Dates |
Last Update Posted: | February 28, 2022 |
Last Verified: | October 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | Data and samples, for subjects who consent to sharing, will be sent to the NIDDK Data and Biological Samples Repository following database lock. |
Supporting Materials: |
Study Protocol Informed Consent Form (ICF) Clinical Study Report (CSR) Analytic Code |
Time Frame: | 2 years after the last visit of the last participant randomized. |
Access Criteria: | Anyone with access to the NIDDK Data and Biological Samples Repository |
URL: | https://repository.niddk.nih.gov/home/ |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Urinary Stone Disease Kidney Stone Urinary Calculi |
Urinary Calculi Urolithiasis Calculi Pathological Conditions, Anatomical Urologic Diseases |