Figure 2

Forest plots showing effect sizes (Hedges’ g) and 95% confidence intervals (CIs) from individual studies and pooled results of all included studies comparing (A) serum ferritin, (B) serum iron, and (C) serum transferrin levels in children with and without ADHD; (D) Forest plot showing effect sizes (Hedges’ g) and 95% CIs from individual studies and pooled results comparing the severity of ADHD symptoms in children with and without iron deficiency (ID); (E) Forest plot pooling the adjusted odds ratio (OR) comparing the association between ADHD and ID. Figure 2(A) serum ferritin levels (p = 0.013) but not (B) serum iron (p = 0.569) or (C) serum transferrin (p = 0.096) levels were significantly lower in the children with ADHD compared to those without ADHD. Figure 2(D) The severity of ADHD symptoms was significantly greater in the children with ID than in those without ID (p < 0.001). Figure 2(E) indicated a significantly high association between ADHD and ID based on the pooled adjusted OR (p = 0.031).