Reducing Salt in the Food Supply Clinical Trial
Official title:
Protocol for a Cluster-randomized Trial to Determine the Effects of a Behavioural Communication Strategy on the Salt Levels of Processed Foods
A clustered-randomized controlled trial in which 45 food companies are the unit of randomization. The intervention companies will receive an advocacy program which comprises of commonly used advocacy actions, incorporating a theory of change model. The control companies will have no specific intervention targeted at them. The aim of this study is to quantify the effects of advocacy delivered by a local non-government organization on the salt content of food products produced or marketed by companies in Australia.
The product formulations of processed packaged foods frequently require added salt. Salt
reduction in these foods is a focus of non-governmental organisations (NGOs) in an effort to
reduce diet related disease. Evidence suggests that advocacy does have the potential to
influence corporate behaviour but few robust data exist to describe the effects of NGO
actions on food companies' salt reduction efforts.
A food composition database was used to select eligible food companies in Australia which
were then classified into three strata based on company ownership, size of company and
industry sector. Of the 45 food companies, 23 were randomised to the control group, and 22
to the intervention. The sample will provide 80% power to detect a difference of 50mg/100g
in mean sodium levels assuming a mean of 430mg/100g, standard deviation of 300mg/100g and
intracluster correlation coefficient (ICC) of 0.05 using a two-sided T-test with a
significance level of 0.05.
The control group will have no specific intervention targeted at them but specific requests
of the study team will be acted upon within the resources available. The intervention group
will receive an advocacy program which comprises of commonly used advocacy actions,
incorporating a theory of change model.
Data for the study will derive from periodic surveys of the characteristics of included
companies, annual surveys of the composition of the processed foods they provide and an
advocacy log recording all elements of the intervention program.
The study is being conducted by an Australian NGO over two years between December 2013-2015.
Ethics approval to collect survey questionnaire and interview data from food companies has
been obtained from the Human Research Ethics Committee at the University of Sydney.
This study will provide evidence about the potential for an Australian advocacy program to
influence corporate behaviour and the quality of the processed food supply in Australia.
Whether the program is effective or not the results, which use a novel experimental
approach, will have important implications for the future of Australian efforts to reduce
the large burden of disease caused by poor diet - a positive finding will highlight the need
for investment in advocacy whilst a negative result will reinforce the importance of other,
policy-based initiatives for the improvement of the food supply.
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