Implementation of a salt substitute intervention using social marketing in resourced-limited communities in Peru: A process evaluation study

Maria Lazo Porras, MD, MSc
Universidad Peruana Cayetano Heredia in Lima

ABSTRACT:
Objective: The goal of this paper is to understand the intervention components and the processes that enabled a successful trial (SALT project). The study focuses on the following six objectives: (i) Identify  contextual factors that play a role in the implementation of the salt substitute, (ii) Identify the mechanisms of action by which participants incorporate the salt substitute in daily life, (iii) Describe the acceptability of the salt substitute and identify their associated factors, (iv) Evaluate the fidelity of the intervention components, (v) Explore the perceptions of the participants surrounding  social marketing campaign components.

Methods: The design of the study is a process evaluation of the SALT project using the Medical Research Council Framework. The main study was a stepped-wedge trial conducted in six villages from Tumbes, Peru. The current study analyzed semi-structured interviews that were conducted to women members from the intervened villages. The intervention consisted in the incorporation of a salt substitute “Liz” (75% sodium and 25% potassium) for free replacing common salt using social marketing strategies. The components of the social marketing campaign were entertainment educational activities and the “Amigas de Liz” that were members from the communities that support the research team. Also, the salt was provided with a spoon (salt Liz spoon) to introduce the right amount of salt that should be used.  The outcomes measured were the context, mechanism of action and implementation outcomes (acceptability, fidelity, attitudes, experiences and perceptions and feedback).

Results: Sixty women were interviews in 4 villages from Tumbes. Some characteristics from the context is that in these villages people eat at home and women are the once responsible to cook. This study identified that Salt Liz was accepted by the villagers where it was implemented. Participants considered Salt Liz healthier than common salt and that it will help them prevent or control hypertension. However, most participants could not explain the components of Salt Liz and common salt. Also, some specific factors from these villages that support the high acceptability were the “high quality” of Salt Liz in comparison to common salt available in those villages or the previous positive experience with a University project related to cysticercosis. 

Those that identified differences between common salt and Salt Liz mentioned that they took around one month to get used to the taste of Salt Liz. Even when the use of Salt Liz was high, the use of the Salt Liz spoon, introduced to guide the right amount of salt was poor. Educational entertainment activities were well-received most participants enjoyed them despite not always being active participants but rather sideline observers. 

Conclusions: This process evaluation identified characteristics that play a positive role that enabled a successful trial. Also, some factors that could be improved were acknowledged.