The Brazilian food security scale for indigenous Guarani households: Development and validation

In Brazil there are 817,963 Indigenous people distributed across 305 ethnic groups, and speaking 274 different languages. The objective of this paper was to develop and validate an experience-based household food security measurement scale among the Guarani people. A mixed-methods study was conducted between 2007 and 2012 in four Guarani communities located on the coast of Sao Paulo. The qualitative phase involved developing an 11-item scale in full consultation and partnership with representatives from the Indigenous communities. Psychometric testing was conducted in 3 villages from 2011 to 2012 by applying the scale predominantly to adult women. Selected nutritional and social indicators were collected for testing the scale's external validity. Psychometric testing was done with the Rasch model (N=88). Severity scores of items followed the theoretically expected ranking order. Nine out of the 11 scale items had an adequate fit to the whole scale (infit values ranging from 0.8 to 1.3). Three of these 9 items had severity scores that were very similar to other scale items indicating redundancy of information and thus two of them were dropped from the scale. The final scale was translated into Guarani confirming the face validity of questions and response options for households with children and adolescents. In conclusion, it was possible to develop a valid experience-based Brazilian Food Security Scale for Indigenous Guarani People (EBIA-G) that can now be tested among diverse Indigenous groups in the country.