Iron Therapy for Improving Psychomotor Development and Cognitive Function in Children Under the Age of Three

A Cochrane review [Abstract] 1 included 8 studies with a total of 385 children less than 3 years of age with iron deficiency anaemia (IDA). Data were only available for children aged less than 26 months of age, and only oral and intramuscular administration routes of iron therapy were addressed and the effects of iron therapy by the intravenous route were not investigated in this review.

Short-term effects of iron therapy (within 30 days): Six studies (n=225) examined the effects of iron therapy on measures of psychomotor development and cognitive function within 30 days of commencement of therapy. Data from 5 studies was pooled. All studies included measures of development before and between 5 to 11 days after commencement of therapy. The pooled differences in pre- to post-treatment changes were not statistically significant: mean difference (MD) in Bayley Scale Psychomotor Development Index (PDI) between iron and placebo groups was -1.25 (95% CI -4.56 to 2.06; 5 studies, n=162) and MD in Bayley Scale Mental Development Index (MDI) was 1.04 (95% CI -1.30 to 3.39; 5 studies, n=164).

Long-term effects of iron therapy (more than 30 days after commencement of therapy): Two studies (n=160) examined the effects of iron therapy on measures of psychomotor development and cognitive function more than 30 days after commencement of therapy. One of the studies reported the mean number of skills gained after 2 months of iron therapy using the Denver Developmental Screening Test. The intervention group gained 0.8 (95% CI -0.18 to 1.78; 1 study, n=97) more skills on average than the control group, although the difference was not statistically significant. The other study reported statistically significant difference in pre- to post-treatment changes in Bayley Scale PDI between iron-treated and placebo groups after 4 months (MD 18.40, 95% CI 10.16 to 26.64; 1 study, n=47) and in Bayley Scale MDI (MD 18.80, 95% CI 10.17 to 27.43; 1 study, n=47).

Comment: The quality of evidence is downgraded by imprecise results (few patients and wide confidence intervals) and indirectness (differences between the outcomes of interest and those reported: very short follow-up, inadequate outcome measure in the largest long-term study).

References

• Wang B, Zhan S, Gong T et al. Iron therapy for improving psychomotor development and cognitive function in children under the age of three with iron deficiency anaemia. Cochrane Database Syst Rev 2013;(6):CD001444. [PubMed].