Putting Prevention into Practice
Screening for Iron Deficiency Anemia Among Children and Adolescents
Am Fam Physician. 2000 Aug 1;62(3):671-673.
Reflecting on your last office session, you recall several pediatric visits. Among these was a visit from a six-month-old infant who was brought in for a checkup and completion of papers for the Women, Infants and Children (WIC) program. You ordered blood work for this infant, because it was required by the program. While most of these blood draws for infants in the WIC program are normal, on occasion, anemia is detected. You begin to wonder if it might be worthwhile to screen all pediatric patients for anemia rather than miss an occasional case.
Which of the following statements is/are correct regarding iron deficiency anemia?
A. Mild iron deficiency (hemoglobin more than 10.5 g per dL [105 g per L]) in the absence of symptoms has only minor health consequences.
B. Sampling of capillary blood specimens yields results comparable to those from venous blood specimens.
C. Older children and adolescent groups with an increased prevalence of iron deficiency anemia include immigrants from developing countries.
D. Correction of more severe iron deficiency anemia (hemoglobin less than 10.5 g per dL) in high-risk infants is associated with improved mental and physical development.
Which one of the following statements is correct regarding screening for iron deficiency anemia among pediatric patients?
A. The USPSTF recommends screening for iron deficiency anemia for all infants from high-risk groups between the ages of six and 12 months.
B. The USPSTF recommends screening for iron deficiency anemia for all infants less than 12 months of age.
C. The USPSTF recommends screening for iron deficiency anemia for all children from high-risk groups between the ages of two and 10 years.
D. The USPSTF recommends screening for iron deficiency anemia for all children at least once between the ages of two and 10 years.
E. The USPSTF recommends screening for iron deficiency anemia for all children at least once before beginning elementary school.
Which one of the following additional laboratory parameters is most useful in the detection of iron deficiency anemia?
A. Mean corpuscular volume.
B. Red blood cell distribution width.
C. Serum ferritin.
D. Serum iron.
1. The answers are A, C and D: evidence of clinical benefit from correction of iron deficiency among older children is limited. Results from studies of clinical outcomes following iron supplementation among older children have also reported inconsistent findings for cognitive improvements.1–3 Multiple observational studies have demonstrated an association between iron deficiency anemia and abnormal growth and development, but it is unclear how much of this is directly attributable to iron deficiency rather than to other environmental factors (e.g., poverty, poor nutrition).
Significantly better mental and motor development after four months of therapy among high-risk children with hemoglobin levels less than 10.5 g per dL4,5 has been demonstrated in the largest of controlled trials on the benefits of correcting iron deficiency, although some other studies have produced inconsistent results.
Studies of malnourished children in developing countries show enhanced growth and weight gain following iron supplementation.6,7 However, whether such results can be generalized to the populations in the United States is uncertain.
While capillary blood sampling is often preferred because of the ease of collection, venous specimens are more reliable for the detection of iron deficiency anemia. Results from one study revealed the capillary microhematocrit to have a sensitivity of 90 percent and a specificity of 44 percent when compared with values obtained from venous blood with an automated cell counter.8 Children and adolescents who have recently immigrated from developing countries should be screened for iron deficiency anemia.9
2. The answer is A : the USPSTF recommends that high-risk infants be screened for iron deficiency anemia between six to 12 months of age. Screening for iron deficiency anemia is not recommended in the general infant population because of low overall prevalence. The Centers for Disease Control and Prevention has developed specific criteria for anemia: hemoglobin levels less than 11.0 g per dL (110 g per L) for children between six months and five years of age.10 In 1993, it was estimated that the prevalence of iron deficiency anemia among children younger than five years was less than 3 percent and most cases were mild11; however, among high-risk groups, the prevalence may be 10 to 30 percent.10 Increased prevalence of iron deficiency anemia occurs among blacks, American Indians, Alaska Natives, persons of low socioeconomic status, preterm and low-birth-weight infants, immigrants from developing countries, and infants whose primary nutritional source is unfortified cow's milk.
Strategies to prevent iron deficiency anemia among infants are recommended. Family physicians should discuss issues of infant nutrition with expectant and new parents and encourage the consumption of iron-fortified formulas and cereals, or encourage breast-feeding supplemented with iron-fortified cereals between the ages of four to six months.12
3. The answer is C: while each of the laboratory parameters listed is useful in arriving at a diagnosis of iron deficiency, only serum ferritin is sufficiently sensitive and specific to be useful in identifying anemic patients.5,13 Mild iron deficiency states may not affect hemoglobin levels.14
1. Pollitt E, Hathirat P, Kotchabhakdi NJ, Missell L, Valyasevi A. Iron deficiency and educational achievement in Thailand. Am J Clin Nutr. 1989;50:687–97.
2. Seshadri S, Gopaldas T. Impact of iron supplementation on cognitive functions in preschool and school-aged children: the Indian experience. Am J Clin Nutr. 1989;50:675–86.
3. Bhatia D, Seshadri S. Growth performance in anemia and following iron supplementation. Indian Pediatr. 1993;30:195–200.
4. Idjradinata P, Pollitt E. Reversal of developmental delays in iron-deficient anaemic infants treated with iron. Lancet. 1993;341:1–4.
5. Centers for Disease Control and Prevention (CDC). Recommendations to prevent and control iron deficiency in the United States. MMWR Morb Mortal Wkly Rep. 1998;4:1–36.
6. Latham MC, Stephenson LS, Kinoti SN, Zaman MS, Kurz KM. Improvements in growth following iron supplementation in young Kenyan school children. Nutrition. 1990;6:159–65.
7. Lawless JW, Latham MC, Stephenson LS, Kinoti SN, Pertet AM. Iron supplementation improves appetite and growth in anemic Kenyan primary school children. J Nutr. 1994;124:645–54.
8. Young PC, Hamill B, Wasserman RC, Dickerman JD. Evaluation of the capillary microhematocrit as a screening test for anemia in pediatric office practice. Pediatrics. 1986;78:206–9.
9. Eddy DM, ed. Common screening tests. Philadelphia American College of Physicians, 1991.
10. Centers for Disease Control and Prevention (CDC). Pediatric nutrition surveillance system. United States, 1980–1991. MMWR Morb Mortal Wkly Rep. 1992;41:1–24.
11. Institute of Medicine Iron deficiency anemia: recommended guidelines for the prevention, detection, and management among US children and women of childbearing age. Washington, D.C.: National Academy Press, 1993.
12. Walter T, Dallman PR, Pizarro F, Velozo L, Pena G, Bartholmey SJ, et al. Effectiveness of iron-fortified infant cereal in prevention of iron deficiency anemia. Pediatrics. 1993;91:976–82.
13. Guyatt GH, Oxman AD, Ali M, McIlroy W, Patterson C. Laboratory diagnosis of iron-deficiency anemia: an overview [published erratum appears in J Gen Intern Med. 1992;7:423]. J Gen Intern Med. 1992;7:145–53.
14. Binkin NJ, Yip R. When is anemia screening of value in detecting iron deficiency? In: Hercberg S, Galan P, Dupin H, eds. Recent knowledge on iron and folate deficiencies in the world. Colloq INSERM. 1990;197:137–46.
The case studies and answers to the following questions on screening for iron deficiency anemia among children and adolescents are based on the 1996 recommendations of the United States Preventive Services Task Force (USPSTF), part of the Put Prevention into Practice program of the Agency for Healthcare Research and Quality (AHRQ), formerly the Agency for Health Care Policy and Research. The answers appear on the following page. The evidence on the efficacy of screening for iron deficiency as well as other USPSTF topics will be reviewed over the next four years; therefore, some of the recommendations may change.
The 1996 recommendations and other information are contained in the “Guide to Clinical Preventive Services,” 2d ed, chapter 22: Screening for Iron Deficiency Anemia, For more information, also consult the “Clinicians Handbook of Preventive Services,” 2d ed, chapter 1: Anemia. The guide and handbook can be viewed on the Web site of the Agency for Healthcare Research and Quality (AHRQ). The AHRQ Web site is http://www.ahrq.gov/clinic. Specific journal references cited in the answers are provided in the discussion.
The Agency for Healthcare Research and Quality would like to thank the staff of the Association of Teachers of Preventive Medicine for their contributions during conceptualization and planning stages of this series.
Copyright © 2000 by the American Academy of Family Physicians.
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