A Brief History of Evidence-Informed Decision Making for Nutrition in Mexico.

The Progresa Conditional Cash Transfer program in Mexico began in 1997, with a strong evidence-based design. The program's ultimate objective was to foster the development of human capital through 3 components-education, health, and food. Rigorous impact evaluation generated evidence of impact on several outcomes, including child growth, but also aspects of program design and implementation challenges that may have limited impact. The objective of this supplement is to present research that led to the redesign of the health component, its implementation and evaluation at pilot scale, and its scale-up to national level, representing >15 y of collaboration among evaluators, program implementers, and funders. The studies used various methodologies, including process evaluation, cohort studies, ethnographic assessments, and a cluster-randomized trial, among others. The articles report previously unpublished results and citations of published literature. Article 1 uses an impact pathway to highlight gaps and bottlenecks that limited potential for greater impact, the original recognition of which was the impetus for this long collaboration. Article 2 explores the social and cultural factors that influence decisions to participate in programs and to adopt the actions proposed by them. Article 3 presents a cluster-randomized trial implemented to inform the choice of nutritional supplements for pregnant and lactating women and children 6-59 mo of age and how this and other evidence from the studies were used to redesign the health component of the program. Articles 4 and 5 present results of the development and pilot testing of the modified health component, the Integrated Strategy for Attention to Nutrition (abbreviated to EsIAN from its name in Spanish) (article 4), and the process and challenges of training and supervision in taking the EsIAN to scale (article 5). The final article provides reflections on the relevance of this body of work for implementation research in nutrition.