Prevention of Urinary Stones With Hydration (PUSH): Design and Rationale of a Clinical Trial.

RATIONALE & OBJECTIVE Although maintaining high fluid intake is an effective low-risk intervention for the secondary prevention of urinary stone disease, many patients with stones do not increase their fluid intake. STUDY DESIGN We describe the rationale and design of the Prevention of Urinary Stones With Hydration (PUSH) Study, a randomized trial of a multicomponent behavioral intervention program to increase and maintain high fluid intake. Participants are randomly assigned (1:1 ratio) to the intervention or control arm. The target sample size is 1,642 participants. SETTING & PARTICIPANTS Adults and adolescents 12 years and older with a symptomatic stone history and low urine volume are eligible. Exclusion criteria include infectious or monogenic causes of urinary stone disease and comorbid conditions precluding increased fluid intake. INTERVENTIONS All participants receive usual care and a smart water bottle with smartphone application. Participants in the intervention arm receive a fluid intake prescription and an adaptive program of behavioral interventions, including financial incentives, structured problem solving, and other automated adherence interventions. Control arm participants receive guideline-based fluid instructions. OUTCOMES The primary end point is recurrence of a symptomatic stone during 24 months of follow-up. Secondary end points include changes in radiographic stone burden, 24-hour urine output, and urinary symptoms. LIMITATIONS Periodic 24-hour urine volumes may not fully reflect daily behavior. CONCLUSIONS With its highly novel features, the PUSH Study will address an important health care problem. FUNDING National Institute of Diabetes and Digestive and Kidney Diseases. TRIAL REGISTRATION Registered at ClinicalTrials.gov with study number NCT03244189.