BackgroundSalt reduction is a cost-effective, and rather challenging public health strategy for controlling chronic diseases. The AppSalt program is a school-based multi-component mobile health (mhealth) salt reduction program designed to tackle the high salt intake in China. This mixed-methods process evaluation was conducted to investigate the implementation of this program across sites, identify factors associated with the implementation, and collect evidence to optimize the intervention design for future scale-up.MethodsMixed methods were used sequentially to collect data regarding five process evaluation dimensions: fidelity, dose delivered, dose received, reach, and context. Quantitative data were collected during the intervention process. Participation rate of intervention activities was calculated and compared across cities. The quantitative data was used for the selection of representative intervention participants for the qualitative interviews. Qualitative data were collected in face-to-face semi-structured interviews with purposively selected students (n = 33), adult family members (n = 33), teachers (n = 9), heads of schools (n = 9), key informants from local health, and education departments (n = 8). Thematic analysis technique was applied to analyze the interview transcripts using NVivo. The qualitative data were triangulated with the quantitative data during the interpretation phase.ResultsThe total number of families recruited for the intervention was 1,124. The overall retention rate of the AppSalt program was 97%. The intervention was implemented to a high level of fidelity against the protocol. About 80% of intervention participants completed all the app-based salt reduction courses, with a significant difference across the three cities (Shijiazhuang: 95%; Luzhou: 73%; Yueyang: 64%). The smartphone app in this program was perceived as a feasible and engaging health education tool by most intervention participants and key stakeholders. Through the interviews with participants and key stakeholders, we identified some barriers to implementing this program at primary schools, including the left-behind children who usually live with their grandparents and have limited access of smartphones; perceived adverse effects of smartphones on children (e.g., eyesight damage); and overlooked health education curriculum at Chinese primary schools.ConclusionThis process evaluation demonstrated the feasibility and acceptability of using smartphone applications delivered through the education system to engage families in China to reduce excessive salt intake.Clinical Trial RegistrationThe AppSalt study was registered at www.chictr.org.cn, identifier: ChiCTR1800017553. The date of registration is August 3, 2018.

BackgroundHigh-salt diet is an important risk factor for several non-communicable diseases. School-based health education has been found effective in reducing salt intake among children and their families in China. However, no such interventions have been scaled up in the real world. For this purpose, a study was launched to support the development and scale-up of an mHealth-based system (EduSaltS) that integrated routine health education and salt reduction and was delivered through primary schools. This study aims to elaborate the framework, development process, features, and preliminary scaling-up of the EduSaltS system.MethodsThe EduSaltS system evolved from previously successfully tested interventions to reduce family salt intake by empowering schoolchildren through school health education. EduSaltS was designed by following the WHO’s conceptual framework for developing a scaling-up strategy which accounted for the nature of the innovation, the capacity of the implementing organizations, the characteristics of the environment, the resources available, and type of scaling up. The system was then developed step by step from determination of online platform architecture, definition of component interventions and activities, development of specific educational materials and tools, to the development of the online/offline hybridized system. The system was tested and refined by a pilot in two schools and a preliminary scale-up in two cities in China.ResultsEduSaltS was developed as an innovative health education system, including an online WeChat-based education platform, a set of offline activities, and an actual administrative website showing the progress and setting the system. The WeChat platform could be installed on users’ smartphones to automatically deliver 20 sessions of five-minute well-structured cartoon video classes, followed by other online interactive activities. It also helps support project implementation and real-time performance evaluation. As a first-stage roll-out, a one-year course has been successfully implemented among 54,538 children and their families from 209 schools in two cities, and the average course completion rate was 89.1%.ConclusionAs an innovative mHealth-based health education system, EduSaltS was developed based on successfully tested interventions and an appropriate framework for scaling up. The early-stage roll-out has shown its preliminary scalability, and further evaluation is ongoing.