Background: Globally, cardiovascular diseases are leading causes of mortality and disability, with hypertension being a major risk factor. Reducing salt intake and blood pressure are among the most cost-effective health promotion strategies. While mobile health (mHealth)– and school-based salt reduction interventions have proven effective in trials, their impact when scaled up in real-world contexts remains uncertain. Objective: We evaluated the effectiveness of the real-world implementation of an mHealth- and school-based health education scale-up program to reduce salt intake (EduSaltS [mHealth and school-based education program to reduce salt intake scaling up in China]). Methods: A parallel cluster randomized controlled trial was conducted from April 2022 to July 2023 across 20 schools in 2 districts and 2 counties within Ganzhou City, Jiangxi Province, China. Schools were randomized 1:1 to intervention or control groups within each district or county. One third-grade class per school and 26 students per class were randomly sampled. One parent, or alternative family member (aged 18-75 years, residing with the student), of each student was invited to join. The EduSaltS intervention, spanning over 1 academic year, incorporated both app-based health education courses and offline salt reduction activities, with participation monitored through the backend management system. The intervention’s effectiveness was assessed by comparing changes in salt intake and blood pressure between groups from baseline to 1-year follow-up using surveys, physical examination, and 24-hour urine tests. Results: Of 524 children (boys: n=288, 54.96%; age: mean 9.16, SD 0.35 years) and 524 adults (men: n=194, 37.02%; age: mean 40.99, SD 11.04 years) who completed the baseline assessments in 10 intervention and 10 control schools, 13 (2.48%) children and 47 (8.97%) adults were lost to follow-up. All schools and participants showed satisfactory intervention adherence. Measured differences in schoolchildren’s salt intake, systolic blood pressure, and diastolic blood pressure, between the intervention and control schools, were –0.24 g/day (95% CI –0.82 to 0.33), –0.68 mm Hg (95% CI –2.32 to 0.95), and –1.37 mm Hg (95% CI –2.79 to 0.06), respectively. For adults, the intervention group’s salt intake decreased from 9.0 (SE 0.2) g/day to 8.3 (SE 0.2) g/day post intervention. Adjusted changes in the intervention (vs control) group in salt intake, systolic blood pressure, and diastolic blood pressure were –1.06 g/day (95% CI –1.81 to –0.30), –2.26 mm Hg (95% CI –4.26 to –0.26), and –2.33 mm Hg (95% CI –3.84 to –0.82), respectively. Conclusions: The EduSaltS program, delivered through primary schools with a child-to-parent approach, was effective in reducing salt intake and controlling blood pressure in adults, but its effects on children were not significant. While promising for nationwide scaling, further improvements are needed to ensure its effectiveness in reducing salt intake among schoolchildren. Trial Registration: Chinese Clinical Trial Registry ChiCTR2400079893; https://tinyurl.com/4maz7dyv (retrospectively registered); Chinese Clinical Trial Registry ChiCTR2000039767; https://tinyurl.com/5n6hc4s2

Background: While the mHealth and school-based scale-up intervention for salt reduction (EduSaltS) effectively reduced salt intake and blood pressure among adults living with participating schoolchildren, the sustainability of these effects remains uncertain. This study aimed to evaluate whether these effects persisted one year post intervention. Methods: A one-year follow-up of a cluster randomized controlled trial was conducted, involving 524 children and their 524 adult family members from 20 primary schools. At 24 months, 509 children (97.1%) and 486 adults (92.7%) completed the assessment. Mixed linear models were used to analyze the difference in changes in salt intake between the intervention and control groups at 24 months, compared to baseline and 12 months, as measured by consecutive 24 h urinary sodium excretions. Secondary outcomes included the differences in changes in blood pressure and salt-related knowledge, attitudes, and practices (KAP) scores. Results: The adjusted mean difference in changes in salt intake between groups was −0.34 g/24 h (95% CI: −0.94 to 0.26, p = 0.265) for children and −0.72 g/24 h (95% CI: −1.48 to 0.05, p = 0.065) for adults at 24 months versus baseline. The corresponding differences from 12 to 24 months were −0.09 g/24 h (95% CI: −0.69 to 0.51, p = 0.775) for children and 0.29 g/24 h (95% CI: −0.50 to 1.08, p = 0.468) for adults. The adjusted difference in changes in adult blood pressure showed a slight, nonsignificant rebound at 24 months. The intervention group maintained significantly higher KAP scores than the control group at both 12 and 24 months. Conclusions: The effects of EduSaltS on reducing salt intake and blood pressure in adults diminished slightly one year after the intervention ended. However, sustained improvements in salt-related KAP were observed in both children and adults. Ongoing support is vital to sustain long-term salt-reduction behaviors.

Background: Reducing dietary salt intake is a global public health priority. However, empirical evidence is needed to clarify whether higher levels of health literacy (HL) and eHealth literacy (eHL), together with the use of diversified information dissemination channels, are positively associated with better salt-related knowledge, attitudes, and practices (KAP). This study examined the indirect associations via eHL and the number of sources of salt-reduction information (NSSI) in the relationship between HL and salt-related KAP. Methods: A cross-sectional survey was conducted from 2022 to 2023 using multistage stratified random sampling among residents aged 15–69 in 22 counties/districts of Jiangxi Province, China. Data on sociodemographic characteristics, HL, eHL, NSSI, and salt-related KAP were collected through face-to-face household interviews using a standardized electronic questionnaire system. Spearman correlation analysis and multiple linear regression were applied to assess associations among HL, eHL, NSSI, and salt-related KAP. Path analysis was employed to evaluate the indirect associations between HL and salt-related KAP via eHL and NSSI. Results: A total of 5396 residents participated, of whom 51.50% were male. Participants aged 15–34, 35–54, and 55–69 years accounted for 13.10%, 42.96%, and 43.94% of the sample, respectively. After adjustment for covariates, individuals with adequate HL, adequate eHL, and a greater NSSI had significantly higher total salt-related KAP scores (p < 0.001). In the path analysis, the standardized direct association of HL with the total salt-related KAP was 0.229 (p < 0.001). The standardized indirect associations via NSSI and eHL were 0.089 (95% CI: 0.069 to 0.111, p < 0.001) and 0.057 (95% CI: 0.033 to 0.089, p < 0.001), respectively, accounting for 23.73% and 15.20% of the total association. Conclusions: High levels of HL and eHL, together with increased exposure to multiple salt-reduction information sources, are associated with improved salt-related KAP. Both eHL and NSSI partially explain the association between HL and salt-related KAP. Future salt-reduction interventions should integrate conventional health education with mobile health technologies to expand information dissemination channels and support sustained salt-reduction behaviors.

Objective: To systematically evaluate the impact of a school-based sodium reduction education program using mobile health (mHealth), known as EduSaltS, on salt-related knowledge, attitudes, practices (KAP) and sodium intake among adults and children during its real-world scaling-up and to examine geographic and population heterogeneity in its effects. Methods: A multi-center pragmatic pre–post study design was used. The EduSaltS program was implemented in three cities (Ganzhou in southern China, Zhenjiang in eastern China, and Qinhuangdao in northern China) between April 2022 and July 2024. Ten primary schools were selected from each city. Baseline and follow-up surveys were conducted approximately 12 months apart, aligned with the school calendar. Electronic questionnaires were used to collect baseline and post-intervention data on the primary outcome—salt-related KAP—from adults and children. In Ganzhou and Zhenjiang, 24 h urine collections were conducted to measure urinary sodium excretion. Results: A total of 721 adults and 770 children were included in the final analysis. After the intervention, the total KAP scores significantly increased in both adults and children across the three sites: by 8.7–10.0 points in adults and by 11.4–16.7 points in children (all p < 0.001). The changes in sodium intake showed significant heterogeneity. A significant decrease in urinary sodium was observed among adults in Ganzhou (−14.0 mmol/24 h, 95% CI: −26.1, −2.0, p = 0.022), corresponding to a reduction of 0.82 g in daily salt intake. No significant change was found among adults in Zhenjiang (adjusted difference: −0.7 mmol/24 h, 95% CI: −13.4 to 12.0, p = 0.912). In children, after the one-year intervention, urinary sodium excretion showed a significant increase from baseline to follow-up in both cities (Ganzhou: +12.9 mmol/24 h, p = 0.018; Zhenjiang: +14.0 mmol/24 h, p = 0.0002). Conclusions: The pre–post evaluation showed that the EduSaltS program was associated with significant improvements in salt-related knowledge across regions. Its effectiveness in reducing sodium intake, however, varied substantially by population and geographic location. The observed increase in children’s urinary sodium excretion may partly reflect normal childhood growth and the limitations of a pre–post design without a control group. Pragmatic randomized controlled trials are warranted to verify the effectiveness of such interventions in reducing sodium intake and blood pressure across diverse populations and settings.

BACKGROUND Globally, cardiovascular diseases are leading causes of mortality and disability, with hypertension being a major risk factor. Reducing salt intake and blood pressure are among the most cost-effective health promotion strategies. While mobile health (mHealth)– and school-based salt reduction interventions have proven effective in trials, their impact when scaled up in real-world contexts remains uncertain. OBJECTIVE We evaluated the effectiveness of the real-world implementation of an mHealth- and school-based health education scale-up program to reduce salt intake (EduSaltS [mHealth and school-based education program to reduce salt intake scaling up in China]). METHODS A parallel cluster randomized controlled trial was conducted from April 2022 to July 2023 across 20 schools in 2 districts and 2 counties within Ganzhou City, Jiangxi Province, China. Schools were randomized 1:1 to intervention or control groups within each district or county. One third-grade class per school and 26 students per class were randomly sampled. One parent, or alternative family member (aged 18-75 years, residing with the student), of each student was invited to join. The EduSaltS intervention, spanning over 1 academic year, incorporated both app-based health education courses and offline salt reduction activities, with participation monitored through the backend management system. The intervention’s effectiveness was assessed by comparing changes in salt intake and blood pressure between groups from baseline to 1-year follow-up using surveys, physical examination, and 24-hour urine tests. RESULTS Of 524 children (boys: n=288, 54.96%; age: mean 9.16, SD 0.35 years) and 524 adults (men: n=194, 37.02%; age: mean 40.99, SD 11.04 years) who completed the baseline assessments in 10 intervention and 10 control schools, 13 (2.48%) children and 47 (8.97%) adults were lost to follow-up. All schools and participants showed satisfactory intervention adherence. Measured differences in schoolchildren’s salt intake, systolic blood pressure, and diastolic blood pressure, between the intervention and control schools, were –0.24 g/day (95% CI –0.82 to 0.33), –0.68 mm Hg (95% CI –2.32 to 0.95), and –1.37 mm Hg (95% CI –2.79 to 0.06), respectively. For adults, the intervention group’s salt intake decreased from 9.0 (SE 0.2) g/day to 8.3 (SE 0.2) g/day post intervention. Adjusted changes in the intervention (vs control) group in salt intake, systolic blood pressure, and diastolic blood pressure were –1.06 g/day (95% CI –1.81 to –0.30), –2.26 mm Hg (95% CI –4.26 to –0.26), and –2.33 mm Hg (95% CI –3.84 to –0.82), respectively. CONCLUSIONS The EduSaltS program, delivered through primary schools with a child-to-parent approach, was effective in reducing salt intake and controlling blood pressure in adults, but its effects on children were not significant. While promising for nationwide scaling, further improvements are needed to ensure its effectiveness in reducing salt intake among schoolchildren. CLINICALTRIAL Chinese Clinical Trial Registry ChiCTR2400079893; https://tinyurl.com/4maz7dyv (retrospectively registered); Chinese Clinical Trial Registry ChiCTR2000039767; https://tinyurl.com/5n6hc4s2