Efficacy Trial of a Mobile Application for Fluid Intake Management in Patients Receiving Chronic Hemodialysis Therapy.

Rationale & Objective: Increased interdialytic weight gain (IDWG) is associated with increased morbidity and mortality in patients receiving chronic hemodialysis. We evaluated the efficacy of a smartphone-based application (app) designed to support reductions in interdialytic fluid intake. Study Design: Pre-post intervention study. Setting & Participants: Adult patients receiving chronic hemodialysis with mean IDWG >3.5% over a 3-month period were recruited from outpatient hemodialysis units in central North Carolina, United States. Intervention: Participants were trained to use a smartphone-based app that allowed recording fluid intake and incorporated behavioral support features (eg, goal setting, prompts, feedback). The patients were asked to use the app daily during the 8-week active phase of the trial. Outcomes: The primary study outcome was the change in mean IDWG from baseline (before app usage) to the 8-week active phase. Secondary outcomes included app safety and usage. IDWG was also assessed during a 6-month passive phase to monitor for possible long-term behavioral changes. Results: Twenty-three patients completed the 8-week active phase and provided app data. Compared with baseline, mean IDWG for the 3-day interdialytic interval decreased by -0.52 ± 0.24 lb ( Limitations: This uncontrolled pre-post study was subject to selection bias toward more technologically literate and adherent participants, did not meet recruitment targets, and lacked urine output data. Conclusions: Use of a smartphone-based app designed to support fluid intake restriction is feasible and associated with sustained reductions in IDWG among patients receiving chronic hemodialysis, without safety concerns.