The Effectiveness of a Behavioral Change Program Integrating the Theory of Planned Behavior and Social Support on Production Quality and Behaviors of Iodized Salt Producers in Maha Sarakham Province

Abstract

This Quasi-experimental research evaluated the effectiveness of an intervention program to improve iodized salt quality by integrating the Theory of Planned Behavior with structured social support among small-scale iodized salt producers in Maha Sarakham Province, Thailand. A one-group pretest–posttest design was employed with 35 purposively selected producers. Data were collected using validated questionnaires measuring production practices, attitudes, subjective norms, perceived behavioral control, and social support, alongside field-based assessments of iodized salt quality. Analyze the data using descriptive and inferential statistics. Compare the means using a Paired t-test, and determine the effect size of the pre- and post-test differences using Cohen’s d.

Post-intervention results demonstrated statistically significant improvements across all behavioral constructs and appropriate production practices (p<0.001). Importantly, the proportion of iodized salt samples meeting national quality standards increased markedly from 67.57% to 100.00%. These findings highlight that the integration between government agencies across different jurisdictions—including District Health Offices/Hospitals under the Ministry of Public Health and Sub-district Health Promoting Hospitals under Provincial Administrative Organizations—combined with the active participation of the Salt Producers' Club in self-regulation, leads to the acceptance and sustainable improvement of production standards. This program is, therefore, suitable to be developed as a model for promoting food quality and safety at the national level.