Public health practitioners increasingly recognize that the proportion of anemia attributable to iron deficiency within populations may not be as large as previously assumed. The Global Burden of Disease Study estimates that thalassemia, hemoglobin deficiency resulting from an inheritable blood disorder, is the second-leading cause of anemia worldwide after iron deficiency. In malaria-endemic countries, other inherited blood disorders are considered important, and their assessment has been incorporated into HIV surveillance systems.

Dietary patterns and environmental conditions, such as altitude and smoke exposure, that influence red blood cell (RBC) synthesis are also important considerations when designing surveillance systems that address different anemia causes. The biological complexities of anemia highlight the need for assessing multiple indicators when diagnosing the causes of anemia in individuals or populations.