Trial Outcomes & Findings for Prevention of Urinary Stones With Hydration (NCT NCT03244189)
NCT ID: NCT03244189
Last Updated: 2025-08-05
Results Overview
Having a symptomatic stone event was defined as meeting any 1 of 2 criteria - stone passage or a procedural intervention for a stone (whether the stone was causing symptoms or not).
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
1658 participants
Primary outcome timeframe
Baseline through approximately 24 months
Results posted on
2025-08-05
Participant Flow
Participant milestones
| Measure |
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.
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.
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.
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.
|
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.
|
|---|---|---|
|
Overall Study
STARTED
|
826
|
832
|
|
Overall Study
COMPLETED
|
676
|
691
|
|
Overall Study
NOT COMPLETED
|
150
|
141
|
Reasons for withdrawal
| Measure |
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.
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.
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.
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.
|
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.
|
|---|---|---|
|
Overall Study
Death
|
0
|
2
|
|
Overall Study
Lost to Follow-up
|
92
|
107
|
|
Overall Study
Physician Decision
|
4
|
2
|
|
Overall Study
Pregnancy
|
7
|
5
|
|
Overall Study
Protocol Violation
|
0
|
2
|
|
Overall Study
Withdrawal by Subject
|
45
|
23
|
|
Overall Study
Technical Problems
|
2
|
0
|
Baseline Characteristics
Prevention of Urinary Stones With Hydration
Baseline characteristics by cohort
| Measure |
Intervention
n=826 Participants
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.
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.
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.
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.
|
Control
n=832 Participants
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.
|
Total
n=1658 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
45 years
n=5 Participants
|
44 years
n=7 Participants
|
44 years
n=5 Participants
|
|
Sex: Female, Male
Female
|
469 Participants
n=5 Participants
|
477 Participants
n=7 Participants
|
946 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
357 Participants
n=5 Participants
|
355 Participants
n=7 Participants
|
712 Participants
n=5 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
46 Participants
n=5 Participants
|
56 Participants
n=7 Participants
|
102 Participants
n=5 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
761 Participants
n=5 Participants
|
757 Participants
n=7 Participants
|
1518 Participants
n=5 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
19 Participants
n=5 Participants
|
19 Participants
n=7 Participants
|
38 Participants
n=5 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=5 Participants
|
3 Participants
n=7 Participants
|
3 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Asian
|
22 Participants
n=5 Participants
|
25 Participants
n=7 Participants
|
47 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
2 Participants
n=5 Participants
|
2 Participants
n=7 Participants
|
4 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Black or African American
|
55 Participants
n=5 Participants
|
58 Participants
n=7 Participants
|
113 Participants
n=5 Participants
|
|
Race (NIH/OMB)
White
|
732 Participants
n=5 Participants
|
719 Participants
n=7 Participants
|
1451 Participants
n=5 Participants
|
|
Race (NIH/OMB)
More than one race
|
7 Participants
n=5 Participants
|
14 Participants
n=7 Participants
|
21 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
8 Participants
n=5 Participants
|
11 Participants
n=7 Participants
|
19 Participants
n=5 Participants
|
|
Region of Enrollment
United States
|
826 Participants
n=5 Participants
|
832 Participants
n=7 Participants
|
1658 Participants
n=5 Participants
|
PRIMARY outcome
Timeframe: Baseline through approximately 24 monthsHaving a symptomatic stone event was defined as meeting any 1 of 2 criteria - stone passage or a procedural intervention for a stone (whether the stone was causing symptoms or not).
Outcome measures
| Measure |
Intervention
n=826 Participants
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.
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.
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.
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.
|
Control
n=832 Participants
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.
|
|---|---|---|
|
Number of Participants With a Symptomatic Stone Event
|
154 Participants
|
165 Participants
|
SECONDARY outcome
Timeframe: Up to approximately 24 monthsOutcome measures
| Measure |
Intervention
n=826 Participants
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.
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.
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.
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.
|
Control
n=832 Participants
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.
|
|---|---|---|
|
Number of Participants With Asymptomatic Formation of New Stone
|
82 Participants
|
83 Participants
|
SECONDARY outcome
Timeframe: Baseline through approximately 24 monthsComparison of the size of any stone on first observation versus later observations or at passage. Will be measured primarily through imaging (CT scan and ultrasound).
Outcome measures
| Measure |
Intervention
n=826 Participants
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.
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.
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.
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.
|
Control
n=832 Participants
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.
|
|---|---|---|
|
Number of Participants With Growth of Existing Stone by ≥ 2 mm in Any Dimension
|
45 Participants
|
32 Participants
|
SECONDARY outcome
Timeframe: Baseline through approximately 24 monthsOutcome measures
| Measure |
Intervention
n=826 Participants
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.
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.
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.
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.
|
Control
n=832 Participants
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.
|
|---|---|---|
|
Number of Participants With Symptomatic Stone Recurrence, Asymptomatic Stone Formation, or Increase of Existing Stone by ≥2 mm in Any Dimension
|
232 Participants
|
236 Participants
|
SECONDARY outcome
Timeframe: 6, 12, 18, and 24 monthsOutcome measures
| Measure |
Intervention
n=826 Participants
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.
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.
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.
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.
|
Control
n=832 Participants
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.
|
|---|---|---|
|
24-hour Urine Total Volume
6 months
|
1.81 L/day
Interval 1.3 to 2.38
|
1.58 L/day
Interval 1.1 to 2.18
|
|
24-hour Urine Total Volume
12 months
|
1.70 L/day
Interval 1.24 to 2.29
|
1.57 L/day
Interval 1.14 to 2.2
|
|
24-hour Urine Total Volume
18 months
|
1.70 L/day
Interval 1.25 to 2.26
|
1.55 L/day
Interval 1.13 to 2.09
|
|
24-hour Urine Total Volume
24 months
|
1.55 L/day
Interval 1.18 to 2.1
|
1.47 L/day
Interval 1.02 to 20.3
|
SECONDARY outcome
Timeframe: Baseline through approximately 24 monthsTo estimate study intervention costs, we will use a tool specifically designed to estimate costs associated with patient-centered interventions (R01NR011873). The costs of medical resource use will be assigned based on payment schedules (e.g., Medicare). To incorporate potential differences in health-related quality of life experienced by participants in the cost-effectiveness analysis, health state utilities will be estimated from existing literature. Full details of the economic analysis will be specified in the Economic Statistical Analysis Plan.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: Baseline, 6, 12, 18, and 24 monthsPopulation: Participants with CASUS data available at each timepoint.
The CASUS is a tool used to assess lower urinary tract symptoms (LUTS) in individuals, providing a comprehensive evaluation of various urinary issues. It's designed to capture a wide range of symptoms, including storage, voiding, post-micturition, urgency, incontinence, and abnormal bladder sensations. The total score ranges from 0 to 38, where a higher score indicates greater urinary symptoms.
Outcome measures
| Measure |
Intervention
n=658 Participants
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.
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.
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.
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.
|
Control
n=661 Participants
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.
|
|---|---|---|
|
Comprehensive Assessment of Self-Reported Urinary Symptoms (CASUS)
Baseline
|
6.11 score on a scale
Standard Deviation 3.298
|
5.94 score on a scale
Standard Deviation 3.311
|
|
Comprehensive Assessment of Self-Reported Urinary Symptoms (CASUS)
6 months
|
6.23 score on a scale
Standard Deviation 3.197
|
6.11 score on a scale
Standard Deviation 3.280
|
|
Comprehensive Assessment of Self-Reported Urinary Symptoms (CASUS)
12 months
|
6.26 score on a scale
Standard Deviation 3.442
|
6.05 score on a scale
Standard Deviation 3.517
|
|
Comprehensive Assessment of Self-Reported Urinary Symptoms (CASUS)
18 months
|
6.11 score on a scale
Standard Deviation 3.267
|
6.11 score on a scale
Standard Deviation 3.459
|
|
Comprehensive Assessment of Self-Reported Urinary Symptoms (CASUS)
24 months
|
6.00 score on a scale
Standard Deviation 3.283
|
6.01 score on a scale
Standard Deviation 3.373
|
Adverse Events
Intervention
Serious events: 0 serious events
Other events: 12 other events
Deaths: 0 deaths
Control
Serious events: 0 serious events
Other events: 2 other events
Deaths: 2 deaths
Serious adverse events
| Measure |
Intervention
n=826 participants at risk
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.
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.
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.
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.
|
Control
n=832 participants at risk
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.
|
|---|---|---|
|
Metabolism and nutrition disorders
Hyponatremia requiring hospitalization
|
0.00%
0/826 • Up to approximately 24 months
"Hyponatremia requiring hospitalization" was the only Serious Adverse Event (SAE) collected for the study. "Asymptomatic hyponatremia" was the only non-serious AE collected.
|
0.00%
0/832 • Up to approximately 24 months
"Hyponatremia requiring hospitalization" was the only Serious Adverse Event (SAE) collected for the study. "Asymptomatic hyponatremia" was the only non-serious AE collected.
|
Other adverse events
| Measure |
Intervention
n=826 participants at risk
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.
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.
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.
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.
|
Control
n=832 participants at risk
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.
|
|---|---|---|
|
Metabolism and nutrition disorders
Asymptomatic hyponatremia
|
1.5%
12/826 • Up to approximately 24 months
"Hyponatremia requiring hospitalization" was the only Serious Adverse Event (SAE) collected for the study. "Asymptomatic hyponatremia" was the only non-serious AE collected.
|
0.24%
2/832 • Up to approximately 24 months
"Hyponatremia requiring hospitalization" was the only Serious Adverse Event (SAE) collected for the study. "Asymptomatic hyponatremia" was the only non-serious AE collected.
|
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place