School-based education programme to reduce salt: Scaling-up in China (EduSaltS)

High salt intake increases the risk of high blood pressure, strokes, heart disease, and several other chronic diseases such as stomach cancer. Salt intake in China is very high with an average of 12-14 gram per day, more than double the WHO recommended level of 5 gram per day.
Unlike the UK and other developed countries, 75%-80% of the salt in the Chinese diet is added by the consumers during cooking or in sauces. An effective strategy to reduce salt from home cooking is of great urgency and importance, not only for China, but also for many other developing countries. However, it is very difficult for individuals to change their eating habits.
Our proposed research will build upon a successfully-tested pilot study entitled "School-based education programme to reduce Salt" (School-EduSalt) in China, in which primary school children were educated, during their usual health education lessons, about the effects of salt on health and how to reduce salt intake. Children then instructed their family members to reduce the amount of salt used during food preparations at home. The results of this pilot study have shown that the school-based education is very effective in reducing salt intake in children and adults. The pilot study was carried out in one city called Changzhi, in northern China.
We now propose to do a study to test whether we can scale up a refined School-EduSalt programme in multiple settings, to reduce salt in larger populations in China, including the poorest population living in the remote and rural areas. This scale-up study will be carried out in three regions of China including Beijing (capital of China), Shijiazhuang (in the north) and Zhenjiang (in the south), covering a population of over 1 million school children and 2.2 million adults.
The study will involve a number of important stakeholders, including governmental organisations, and the health and education authorities of the three regions. Based on WHO's Conceptual Framework for Scaling up, we will work with these stakeholders to develop, implement and evaluate a feasible scale-up package, which will be integrated into the existing school health education system to ensure sustainable scaling-up.
The scale-up package will be evaluated in three aspects: effectiveness, process and health economics. We will assess whether the education programme can improve the participants' knowledge, attitudes and practices towards salt reduction. Additionally, we will assess whether the education programme can achieve a sustainable reduction in salt intake which will be measured by the gold standard method of 24-hour urine collection.
Our ultimate aim is to incorporate the refined education programme into the national school curriculum, so that all schools in China will follow. A nation-wide implementation will have an enormous impact on reducing population salt intake. A reduction in salt intake across the whole population, even by a small amount, will lower population blood pressure and prevent hundreds of thousands of strokes, heart attacks and heart failure each year, and also lead to major cost-savings to individuals, their families and the health service.

Based on the WHO's Conceptual Framework for Scaling up, our proposed research aims to conduct a scale-up study on the school-based education programme to reduce salt in China with an implementation science approach. We will use one group pre-post design with mixed (both qualitative and quantitative) methodology. The study will be carried out in 3 regions, i.e. Beijing (the capital of China), Shijiazhuang in the north and Zhenjiang in the south with a population of >1 million children and 2.2 million adults.
The study will follow a 4-phase model of implementation spanning preparation (0.5 yr), pilot (0.5 yr), scale-up study (2 yrs), and national roll-out and sustainment phase (1 yr).
During the scale-up study, a refined education programme will be implemented in grade 4 (aged approximately 10 yrs) in all primary schools. We will conduct 3 representative cross-sectional surveys to assess the changes in KAP (Knowledge, Attitudes and Practices) and salt intake (measured by 24h urinary sodium), at baseline (yr 0), at the end of the 1-yr intervention (yr 1), and after an additional year of follow-up (yr 2), with an aim of evaluating the effect of the intervention and its sustainability. KAP questionnaires will be completed in a randomly selected sample of 4050 children from 54 schools, and 8100 adult family members. Salt intake will be assessed by 24h urinary sodium excretion in a randomly selected sample of 726 children from 33 schools and 726 adult family members.
The primary outcome is the change of salt-related KAP, and the secondary outcome is the change of salt intake in children and their families as measured by 24h urinary sodium. Process evaluation will be conducted to assess the uptake rate of the scale-up package, and to examine facilitators and barriers to implementation. For health economic evaluation, an incremental cost effectiveness ratio will be calculated.

Our research will achieve a broad range of impacts. The biggest impact is on the policy, with the local education/health authorities issuing policies to support the scale-up study and the scale-up package integrated into the existing school health education system. This will set a good model for other regions in China to follow, leading to larger influence on national rollout. The school-based salt reduction programme will also be integrated into the on-going national Health Promoting School Initiative, so that all schools in China will implement the programme.
The research will have an important academic impact, advancing the scientific knowledge across and within various disciplines, e.g. nutrition, blood pressure, public health, school education, particularly enhancing the understanding and application of the theories, methodologies and practices of the implementation and translational sciences, which will bridge the knowledge gap between the effective interventions and their translation into daily practice. Chinese researchers will be the major beneficiaries in this regard, with enhanced knowledge and skills for translating the research output into policy.
Most importantly, our scale-up study will achieve an enormous impact on health and the economy. The immediate benefit from a reduction in salt intake is to lower blood pressure. For adults, this will have a significant effect on reducing the risk of suffering a stroke, heart attack or heart failure. For children, a lower salt intake will prevent the development of high blood pressure and cardiovascular disease later in life. A reduction in salt intake not only saves lives, but also saves money for individuals, their families and the health service.
Furthermore, our study will contribute to the promotion of healthy diets and lifestyle among Chinese population including both adults and children who will maintain the healthy lifestyle with the knowledge and skills developed at an early age throughout their lifetime.
Last but not the least, global health impact will be achieved through dissemination and adaptation of our research outputs to other countries. In this regard, we will seek various opportunities to work with WASH (World Action on Salt and Health), WHO Collaborating Centre for Population Salt Reduction, Queen Mary University of London's global development network, the NIHR large cohort of Global Health Research Units and Groups, Global Alliance of Chronic Diseases (GACD)'s network to translate our findings to other settings in the world.