Following state-of-the-art presentations and discussion on each determinant, participants used a simple matrix to look at all determinants concurrently and with respect to age, sex, and population physiologic subgroup. The matrix, developed using the example of sub-Saharan Africa, was used to assess the relative importance of each determinant for each age group. As a result of the exercise, it was apparent that, for sub-Saharan Africa, the most important determinant of anemia at every stage of the life cycle, except pregnancy and infant, was diet, particularly bioavailability of iron. In pregnant women, malaria was the main determinant of anemia in malarious areas for primigravidae, and both inadequate iron intake and low bioavailability were the main determinants in multigravidae. Malaria and diet were the main determinant in infants in the first year of life in malarious areas. The exercise revealed that casualty is a complex matrix that is locality specific. Participants identified gaps in knowledge and recognizes the need for simple epidemiologic methods to assess the causes of malaria.