NoToNa: Tackling cardiovascular risk in the adolescent life-course through a schools' salt-reduction intervention in sub-Saharan Africa

Lead Research Organisation: London Sch of Hygiene and Trop Medicine
Department Name: Epidemiology and Population Health

Abstract

High blood pressure, which can lead to strokes, heart disease and kidney disease, is an increasing problem in sub-Saharan Africa, and starts young. Excessive salt intake is a major contributor to this. In some countries salt intake has been tackled through regulation of the processed food industry, but in much of sub-Saharan Africa little processed food is eaten and most salt is added at home. In Malawi we already have evidence of worrying levels of high blood pressure in teenagers, and high salt consumption.

Working with the School Health and Nutrition Programme, we propose to conduct a trial of an intervention package in schools in rural and urban Malawi which aims to reduce salt consumption in adolescents and their families. Of 26 schools, half will be randomized to receive the intervention and half will receive the normal school curriculum. The intervention will take place over one school term and will be delivered to children in Year 6. It will include lectures, discussions, homework including food diaries, competitions, drama and family quizzes. It is modelled on a successful intervention in China, and will be adapted for local use.

We will measure the effect of the intervention by measuring salt excretion (in urine) and blood pressure in a random sample of 20 children per school and their parents/guardians. We will compare the change in measurements from baseline to end of the intervention in participants from intervention and control schools, and will measure again at one year to assess the persistence of any effects of behaviour change. We will also assess factors that have helped or hindered implementation of the intervention, and will measure cost-effectiveness. This will be very important in deciding whether and how to scale up the intervention.

Technical Summary

Hypertension, a risk factor for strokes, cardiovascular and renal disease, is increasing in sub-Saharan Africa, and starts young. WHO has identified salt reduction as one of the "best buys" to reduce cardiovascular disease in low income countries. In much of sub-Saharan Africa most sodium intake is from salt added at home, so measures tackling processed food that have worked elsewhere would have little impact. In Malawi we have already found hypertension in teenagers (5.1% males and 2.3% females aged 18-19) with levels increasing rapidly with age. Salt consumption is high: more than half of the adults exceeded recommended limits from plain salt alone.

Working with the School Health and Nutrition Programme, we propose to conduct a cluster-randomized trial of an educational/behavioural intervention package in schools in rural and urban Malawi which aims to reduce salt consumption in adolescents and their families. Of 26 schools, half will be randomized to receive the intervention and half will receive the normal school curriculum. The intervention will take place over one school term and will be delivered to children in Year 6 (aged 11-14). It will include lectures, discussions, homework including food diaries, competitions, drama and family quizzes. It is modelled on a successful intervention in China, and will be adapted for local use.

We will measure the effect of the intervention by measuring 24-hour urinary sodium and blood pressure in a random sample of 20 children per school and their parents/guardians at baseline, at the end of the intervention, and one year later (to assess persistence of any effects). We will compare the change in measurements from baseline in participants from intervention and control schools. Process evaluation will include identifying barriers and facilitators to the intervention, and we will also estimate cost-effectiveness. These factors will be critical in deciding whether and how to scale up the intervention.

Planned Impact

The project could have substantial impact both for its empirical findings, and their potential to change the health and lifestyle on a large scale, and in methodological terms.
Excessive salt intake as a cause of high blood pressure is a huge and increasing problem. Few studies have assessed how to reduce it in sub-Saharan Africa. A cost-effective and scaleable intervention is needed, and a school-based intervention could be both easily scaleable and relatively cheap.
If successful this intervention could reduce hypertension (and therefore the risk of stroke, cardiovascular and renal disease) not only of the adolescents but of their families. Embedded social science and economics studies will enable us to establish how best to implement it and make it cost effective. Because we work closely with the School Health and Nutrition programme (a joint Ministry of Health and Ministry of Education, Science and Technology initiative) who are committed to developing healthy eating programmes, the potential to scale the intervention up across the country is immediately there. If the programme became part of the curriculum it would reinforce the learning in households and the community.
Many other areas of Africa have similar diets, and the programme could be implemented more broadly. Because the diseases it helps to prevent are common and costly the impact could have economic and social impacts as well as the direct impact on health.
Understanding and evaluating behavioural interventions such as this requires a multidisciplinary team to integrate the cluster randomized trial with qualitative and economic measurements. The trial will help build capacity for assessing complex interventions and implementation science. Furthermore, now that primary school enrolment is high in most countries, at least initially, the potential for delivering other health interventions through schools could be explored.

Publications

10 25 50
 
Title Artistic competition 
Description Learners that participated in the in the intervention co-created drama, poems, stories and songs with their teachers to showcase what the intervention had taught them. The topics included advantages and disadvantages of salt, the strategies to reduce salt and examples of people that use a lot salt in the learners' home environment. These artistic products were presented to the participating schools learners and judging panel that comprised of one study team member, the head teacher and a primary school adviser. The judging was based on the content, truthfulness of the content, whether the product stimulated the audience. The competition was within schools and the winners competed at inter school level. The groups that won were given prizes in form of pens, rulers, mathematical instruments and school bags. 
Type Of Art Performance (Music, Dance, Drama, etc) 
Year Produced 2020 
Impact The learners were able to share their experiences participating in the intervention with their fellow learners in other classes that did not participate in the intervention. The learners also found it exciting to participate in the intervention because it took a different approach of teaching than the normal science classes. And the teachers found this teaching method very appealing for them and the learners. 
 
Title Illustrations for educational materials on sodium reduction for school children in Malawi 
Description Primary school science lesson (and home) materials in English, Chichewa, Tumbuka (pamphlets, workbooks, posters) created to support educational intervention. Illustrated with culturally and setting specific cartoons by a local illustrator. 
Type Of Art Artwork 
Year Produced 2020 
Impact Trial outcome awaited, but materials performed very highly in qualitatively assessed process indicator work with students, teachers and families. 
 
Description Process of stakeholder engagement and sharing sodium reduction strategies
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
 
Description Regular member of NCD policy workshops - setting national strategies, policies and guidelines
Geographic Reach National 
Policy Influence Type Gave evidence to a government review
 
Title Design of pilot project to evaluate measurement of sodium excretion in urine 
Description Pilot study to be conducted collecting fractionated 24 hour urine to be able to model the impact of missing voids on overall analysis of 24 hour urinary sodium excretion (the standard tool for measurement of excess sodium intake) 
Type Of Material Physiological assessment or outcome measure 
Year Produced 2019 
Provided To Others? No  
Impact Will inform the trial and evaluation of other sodium reduction trials in any setting 
 
Title Final survey/sample collection tools & SOP 
Description Conducting the longitudinal surveys for this trial required the collection of 24 hour urine samples from ~2,000 individuals and link this to a series of individual and household level questionnaires conducted by a large team of data collectors across two sites and over 18 months. The survey/sample collection tools include the individual-level anthropometric and dietary questionnaires in addition to household-level dietary and expenditure questionnaires. The attached SOP was used to train, deploy and supervise data collectors and includes a detailed data collectors manual, training & assessment materials, print-formatted questionnaires and the xls forms compatible with Open Data Kit (ODK). 
Type Of Material Physiological assessment or outcome measure 
Year Produced 2021 
Provided To Others? No  
Impact These tools and SOP have been shared internally to inform data collection for other large-scale research activities. On publication of the final analysis this package will be made available on a publicly accessible platform also used to archive the final datasets. 
 
Title Final analysis dataset for NoToNa Trial 
Description Baseline, end of Term and 1 year follow up data for adolescents and adults enrolled in trial. Includes household salt usage, individual dietary questionnaires, 24-hour urinary sodium (not one year follow-up), blood pressure 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? No  
Impact Undergoing analysis and will subsequently be made publicly available 
 
Title Development of primary school science curriculum package on sodium reduction in low income Africa 
Description Education (science and nutrition curriculum and associated activities) package on sodium reduction appropriate for low income rural and urban primary school children. Funding is to evaluate this in a cluster randomised trial. 
Type Preventative Intervention - Nutrition and Chemoprevention
Current Stage Of Development Initial development
Year Development Stage Completed 2019
Development Status Under active development/distribution
Impact Development process (and we hope success in implementation) is bringing Ministries of Health and Education together to tackle non-communicable disease from its early life origins for the first time in Malawi. 
 
Description Bringing together Ministries of Health and Education on development of sodium reduction education package 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Policy makers and ministry stakeholders participating in workshops on sodium reduction,
Year(s) Of Engagement Activity 2018,2019
 
Description Community Consultations 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Study participants or study members
Results and Impact We had consultation events held within the study sites where invitation were extended to the community through the chiefs of the different study areas that the No-to-Na- trial engaged with. The purpose of the events was to consult the study site on the new research studies that were planned in these areas. As part of the event, the study results of No-to-Na trial were shared with the communities. The consultation sessions used participatory artistic based methods to inform but also disseminate study results. There were between 50 and a 100 people attending each session. We held over 10 sessions in both the urban and rural sites. The results stimulated discussions that helped prepare the communities on the impending new studies but also sparked discussion of dissemination of study results sooner than later.
Year(s) Of Engagement Activity 2021
 
Description Regular planning and update meetings with education-sector stakeholders 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Study participants or study members
Results and Impact Throughout the NoToNa study, prior to each large-scale implementation activity (e.g. teacher training), evaluation activity (e.g. urine collection) or study phase (e.g. close-out of data collection) regular meetings were held with stakeholders from across the education sector at local, regional and national levels to review the previous phase, resolve challenges, and provide updates on progress and future plan. This dialogue greatly facilitated successful implementation of the study including high fidelity to the intervention by schools and high participant follow-up.
Year(s) Of Engagement Activity 2019,2020,2021
 
Description School-based interventions interest group/Research consortium for SHN 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact NoToNa study was featured in School-based interventions interest group during the establishment of the Research Consortium for SHN hosted at LSHTM. Study has been presented under themes of (1) 'Integration of health-based interventions in schools' (focus of presentation - process of successfully integrating within the school curriculum and between government departments) and (2) 'What to include in the intervention?' (focus of presentation - how school health interventions can be used as mechanism to also engage with parents/household members of school children). Presentations were well received and prompted lots of questions and feedback from audience.
Year(s) Of Engagement Activity 2020,2021
 
Description Virtual Conference Presentation 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact This was the 16th international Congress of Behavioral Medicine (ISBM) conference that was held in Glasgow with the theme "Interdisciplinary behavioral Medicine: systems, network and interventions." The conference showcased 704 cutting edge research from 49 countries across the globe. Our main purpose was to disseminate our study results but also learn from different pieces of work done elsewhere. We also benefitted from the networking platforms that the conference provided. This was a worthwhile experience since it was held during Covid lockdown as such it gave us a virtual conference experience.
Year(s) Of Engagement Activity 2021