The WHO Global Database on Anemia provides estimates of anemia prevalence at the country, regional, and global levels using blood concentration as the indicator. Thresholds to establish normal ranges of hemoglobin for the different physiological groups of populations (children, adolescents, adults and pregnant women) were defined at a WHO Expert Consultation held in Geneva in 1992.

Survey reports and publications reporting the prevalence of anemia used in the WHO Global Database on Anemia were collected from: ministries of health through WHO regional offices, national research and academic institutions, nongovernmental organizations, organizations in the UN system, and regular searches of online databases such as PubMed, Medline, Embase, Ovid, and WHO regional databases.