Anaemia: iron-deficiency anaemia is relatively common in menstruating women and toddlers.

Clinical bottom line (level 2c)

  1. Iron deficiency anaemia is relatively common in menstruating women (~4%) and toddlers (~3%).
  2. It is uncommon in men until old age.
Looker et al: Journal of the American Medical Association 1997; 277 (12): 973-976
Expires September 2003

The study

Outcome study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: civilian non-institutionalised population, USA

24894 patients (aged >1 year, ?% male) individuals participating in National Health and Nutrition Examination Survey (1988-1994)

Excluded if
  • less than one year old
  • pregnant
Outcomes studied:
  • Participants were 86% of the examined sample.
  • All patients had household interviews and standardised physical examination and phlebotomy. They had blood counts, serum iron and total iron binding capacity, serum ferritin and red cell protoporphyrin.
  • Iron-deficiency anaemia diagnosed if any two of:
    • transferrin saturation (typically <15%)
    • serum ferritin (typically <12 mcg/l)
    • red cell protoporphyrin abnormal (typically >1.24 micromol/l)
    and
    • low haemoglobin (male <12.4 g/dl; female <11.8 g/dl)

The evidence


  • Cut-offs varied for age and sex (and adjusted for confounding, based on previous survey 95% confidence intervals).
    • children aged 1-2 (n=1339)- iron-deficiency anaemia 3%
    • aged 3-5 (n=2334)- iron-deficiency anaemia <1%
    • aged 6-11 (n=2813)- anaemia <1%
    • women aged 12-15 (n=786)- anaemia 2%
    • women aged 16-19 (n=700)- anaemia 3%
    • women aged 20-49 (n=4495)- anaemia 5%
    • women aged 50-69 (n=2034)- anaemia 2%
    • women aged 70 or more (n=1630)- anaemia 2%
    • men aged 12-15 (n=691)- anaemia <1%
    • men aged 16-19 (n=658)- anaemia <1%
    • men aged 20-49 (n=4048)- anaemia <1%
    • men aged 50-69 (n=1929)- anaemia 1%
    • men aged 70 or more (n=1437)- anaemia 2%
  • Iron deficiency was found to be commoner on multivariate regression analysis in:
    • non-white women
    • women with more children

Comments

  1. These results support the US Preventative Task force recommendation on screening for iron deficiency anaemia.

Citation

  1. Looker AC, Dallman PR, Carroll MD, et al: Prevalence of iron deficiency in the United States. Journal of the American Medical Association 1997; 277 (12): 973-976
Contributor: Chris Ball and Clare Wotton, June 2000
Reviewer: Tadao Okada and Sukanya Srinivasan

Clinical Question.
Patient participants of NationalHealth and Nutrition Examination Survey
Intervention or Exposure prevalence
Outcome iron-deficiency anaemia