Verifying validity of the household dietary diversity score: an application of rasch modelling

The Household Dietary Diversity Score (HDDS) was developed to measure household food access, one of the levels of food security. Previous research has shown dietary diversity is related to food security. However, the specific way in which the HDDS measures food security has never been validated. Based on the results of a Rasch model on datasets from Colombia and Ecuador we conclude this indicator in its current form is not internally valid, has limited external validity only in our Colombian data, and is not comparable across cultural settings. More research is warranted into the food groups that make up the indicator as well as the recall period on which it is based.