高血圧患者の臨床転帰に対するナトリウム摂取量モニタリング用スマートフォンアプリ（NamakBan）の有効性：無作為化比較試験

AIM: To evaluate the effectiveness of NamakBan, a smartphone application for monitoring sodium intake, on blood pressure, dietary sodium consumption, urinary sodium-to-potassium ratio and hospitalization in adults with primary hypertension. DESIGN: We conducted a parallel randomized clinical trial at the specialized hypertension clinic of Shahid Modarres Hospital in Tehran, Iran. METHODS: Between April 1, 2024, and September 20, 2025, 88 patients with physician-diagnosed primary hypertension were randomized (1:1) to receive standard clinic care (control, n = 44) or standard care plus the NamakBan app (intervention, n = 44). The app (Android) allowed repeated self-reporting of blood pressure and salt intake, medication logging, and PDF output for monitoring. Outcomes were assessed at baseline, 1 month and 2 months. Primary outcomes were systolic and diastolic blood pressure; secondary outcomes were self-reported dietary sodium intake, urinary Na/K ratio and readmissions. RESULTS: Baseline characteristics were balanced. Compared with the control, the experimental group showed greater reductions in systolic blood pressure and diastolic blood pressure. Self-reported daily sodium intake declined more in the experimental arm than in the control. Urinary Na/K ratio decreased within the experimental group over time, but between-group differences were not significant. No hypertension-related hospital readmissions were recorded in the intervention group, whereas four readmissions occurred in the control group; however, this difference was not statistically significant. CONCLUSIONS: In this RCT, the NamakBan application, used alongside usual care, was associated with modest but statistically significant improvements in systolic blood pressure, diastolic blood pressure and self-reported sodium intake over 2 months. However, the objective urinary sodium-to-potassium ratio did not differ between groups. The findings should therefore be interpreted with caution: dietary sodium was assessed via unblinded self-report, follow-up was limited to 2 months, the trial was single-centre and the application was available only on Android. IMPLICATIONS FOR PATIENT CARE: Integration of such applications into routine nursing and clinical follow-up may improve outcomes and potentially reduce hypertension-related hospital readmissions. IMPACT: What problem did the study address?: Inadequate monitoring of dietary sodium intake and limited patient engagement in self-management contribute to poor blood pressure control in adults with primary hypertension. Few randomized trials of sodium-focused applications report an objective biochemical measure alongside self-reported intake or health-service outcomes such as readmission. What were the main findings?: Use of the NamakBan smartphone application, in addition to usual care, led to significant reductions in systolic and diastolic blood pressure and an improvement in self-reported sodium intake. No hypertension-related hospital readmissions were observed in the intervention group; however, the between-group difference was not statistically significant. Where and on Whom Will the Research Have an Impact?: This research will benefit adults with primary hypertension and inform nursing practice and outpatient hypertension care, particularly by integrating mobile health interventions into routine clinical follow-up and patient education. REPORTING METHOD: Consolidated Standards of Reporting Trials (CONSORT). No Patient or Public Contribution. TRIAL REGISTRATION: Iranian Registry of Clinical Trials (IRCT): registration code IRCT20240207060927N1.