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 (P = 0.032) during the active phase and -0.86 ± 0.96 lb (P < 0.01) during the passive phase. No safety concerns (defined as >50% increase in IDWG) were observed. During the active phase, app was used on ≥80% of the days by 65% of participants and daily by 26% of participants. Reductions in IDWG were sustained during the passive phase. Correlations between app-recorded fluid intake and IDWG were weak and not statistically significant.

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.