The Proportion of Anemia Associated with Iron Deficiency in Low, Medium, and High Human Development Index Countries: A Systematic Analysis of National Surveys.
Iron deficiency is commonly assumed to cause half of all cases of anemias, with hereditary blood disorders and infections such as hookworm and malaria being the other major causes. In countries ranked as low, medium, and high by the Human Development Index, we conducted a systematic review of nationally representative surveys that reported the prevalence of iron deficiency, iron deficiency anemia, and anemia among pre-school children and non-pregnant women of reproductive age. Using random effects meta-analyses techniques, data from 23 countries for pre-school children and non-pregnant women of reproductive age was pooled, and the proportion of anemia attributable to iron deficiency was estimated by region, inflammation exposure, anemia prevalence, and urban/rural setting. For pre-school children and non-pregnant women of reproductive age, the proportion of anemia associated with iron deficiency was 25.0% (95% CI: 18.0, 32.0) and 37.0% (95% CI: 28.0, 46.0), respectively. The proportion of anemia associated with iron deficiency was lower in countries where anemia prevalence was >40%, especially in rural populations (14% for pre-school children; 16% for non-pregnant women of reproductive age), and in countries with very high inflammation exposure (20% for pre-school children; 25% for non-pregnant women of reproductive age). Despite large heterogeneity, our analyses suggest that the proportion of anemia associated with iron deficiency is lower than the previously assumed 50% in countries with low, medium, or high Human Development Index ranking. Anemia-reduction strategies and programs should be based on an analysis of country-specific data, as iron deficiency may not always be the key determinant of anemia.
GroundWork, Fläsch 7306, Switzerland. nico@groundworkhealth.org.
Nicolai
N
Petry
GroundWork, Fläsch 7306, Switzerland. ioo523@mail.harvard.edu.|Department of Epidemiology; Harvard School of Public Health, Boston, MA 02115, USA. ioo523@mail.harvard.edu.
Ibironke
I
Olofin
Laboratory of Human Nutrition, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich 8092, Switzerland. richard.hurrell@hest.ethz.ch.
Richard F
RF
Hurrell
Harvest Plus, International Food Policy Research Institute, Washington, DC 20006, USA. E.Boy@cgiar.org.
Erick
E
Boy
GroundWork, Fläsch 7306, Switzerland. james@groundworkhealth.org.
James P
JP
Wirth
Harvest Plus, International Food Policy Research Institute, Washington, DC 20006, USA. m.moursi@cgiar.org.
Mourad
M
Moursi
Harvest Plus, International Food Policy Research Institute, Washington, DC 20006, USA. m.angel@cgiar.org.
Moira
M
Donahue Angel
GroundWork, Fläsch 7306, Switzerland. fabian@groundworkhealth.org.
Fabian
F
Rohner
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D019049:Developed Countries; D003906:Developing Countries; D005260:Female; D006304:Health Status; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007249:Inflammation / Q000453:epidemiology; D007501:Iron / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D055815:Young Adult
D015415:Biomarkers; D007501:Iron
anemia; determinants of anemia; iron deficiency; iron deficiency anemia