MIXED-METHOD PROCESS EVALUATION PROTOCOL OF A RANDOMIZED CONTROLLED TRIAL OF AN APP-BASED EDUCATION PROGRAM TO REDUCE SALT INTAKE IN SCHOOL CHILDREN AND THEIR FAMILIES IN CHINA

Abstract

Objective: Dietary salt intake is a major risk factor for high blood pressure. It is extremely challenging to reduce salt intake in China, with about 80% being added by the consumers. In recognition this challenge, an innovated salt reduction intervention package (AppSalt) based on smartphone application with functional modules of education, evaluation, target setting and monitoring, decision support and management, was developed and applied among school children and their family members. Process evaluations are crucial for understanding how and why the interventions resulted in its observed effect in this setting, but also inform transferability and future implementation in many other countries. This protocol is to describe the methodology of the process evaluation of AppSalt program, to promote transparency and share the approach, which can be adapted for use in other complex interventions. Design and method: We describe the pragmatic methods on five process evaluation dimensions: The fidelity of the implementation, intervention dose delivered and received, reach of the intervention strategies, and the contextual factors influencing the intervention, informed by the theoretical framework of process evaluation proposed by Linnan and Steckler. Quantitative and qualitative data will be triangulated to provide a clearer picture of the AppSalt implementation in the real world. Mixed methods will be used for collecting and analysis the process data. The APP usage log, activity logs, routinely collected monitoring data and mid-term survey will be the major quantitative process data source to analyse the fidelity, reach and dose of intervention strategies. To understand participants’ experiences and the causal mechanism of the intervention strategies, semi-structured interview will be used for purposively selected intervention participants and key stakeholders from local health and education authorities. Results: This is a protocol paper. Data collection is still ongoing. Therefore, there is no results in this abstract. Conclusions: This protocol provides a good example of how to integrate process evaluation into public health interventions. It will be helpful for other researchers and policy-makers to replicate the evidence of AppSalt program and design their own salt reduction program.