TABLE 2.
Summary of intervention effect sizes for hemoglobin concentrations and anemia1
| Outcome: Hb, g/dL | Outcome: anemia | |||||
|---|---|---|---|---|---|---|
| Interventions | References | Population group | n | MD (95% CI; P value when NS) | n | RR (95% CI) |
| Daily iron supplementation | (13, 19–43) | Children <5 y | 106 | 1.675 (1.468, 1.882)*** | 29 | 0.588 (0.503, 0.686)*** |
| Children ≥5 y | 46 | 0.836 (0.638, 1.035; P = 0.101) | ||||
| Intermittent iron supplementation | (13, 19–43) | Children <5 y | 19 | −0.097 (−0.193, −0.001)* (vs. daily iron) | 3 | 1.340 (0.943, 1.906; P = 0.103) (vs. daily iron) |
| 12 | 0.645 (0.334, 0.956)*** (vs. placebo) | 3 | 0.403 (0.183, 0.889)* (vs. placebo) | |||
| Children ≥5 y | 6 | −0.044 (−0.217, −0.130; P = 0.088) (vs. daily iron) | 5 | 0.738 (0.569, 0.957)* (vs. placebo) | ||
| 10 | 1.606 (0.717, 2.495)*** (vs. placebo) | ND | ND | |||
| Daily IFA | (13, 27, 40, 12, 44–46) | Women at or near term (34 wk) | 6 | 1.61 (1.37, 1.85)*** | 4 | 0.34 (0.25, 0.47)*** |
| Mothers 6 wk postpartum | 4 | 1.01 (0.81, 1.2)*** | ND | |||
| Women at term (37 wk) | ND | ND | 5 | 0.31 (0.23, 0.42)*** | ||
| Intermittent IFA | (13, 27, 29, 40, 12, 44–46) | Women near or at term (34 wk) | ND | ND | 5 | 1.24 (0.96,1.59; P = 0.098) |
| Women at term (37 wk) | ND | 7 | 1.38 (0.94, 2.03; P = 0.1) | |||
| MNP | (47–51) | Children <5 y | 6 | 2.663 (−0.611, 5.938; P = 0.111) | 12 | 0.689 (0.615, 0.773)*** |
| Folate | (52) | Pregnant women | 12 | −0.03 (−0.25, 0.19)*** | 8 | General anemia: 0.62 (0.35, 1.10; P = 0.1) |
| ND | 4 | Megaloblastic anemia: 0.21 (0.11, 0.38)*** | ||||
| Malaria treatment | (53–57) | All ages | 6 | Day 28: 0.12 (0.03, 0.21)** | 3 | 0.93 (0.77, 1.12; P = 0.451) |
| 4 | Day 42: 0.26 (0.08, 0.44)** | ND | ND | |||
| IPTp | (58–67) | Pregnant women | 5 | 0.41 (0.27, 0.54)*** | 23 | 0.9 (0.84, 0.95)*** |
| ITN | (68–70) | Children <5 y | 4 | 0.7 (0.44, 0.97)*** | 5 | 0.91 (0.7, 1.18; P = 0.46) |
| Pregnant women | 11 | 0.05 (−0.12, 0.23; P = 0.539) | 5 | 0.9 (0.77, 1.06; P = 0.195) | ||
| Deworming | (71–75) | Children <5 y | 8 | −0.008 (−0.069, 0.052; P = 0.789) | ||
| Children ≥5 y | 8 | 0.051 (−0.072, 0.175; P = 0.415) | 6 | 0.875 (0.816, 0.940)*** | ||
| Delayed cord clamping | (76–87) | Full-term newborns | 4 | Hb at birth: 1.94 (0.76, 3.11)*** | 4 | Outcome is risk for transfusion: 0.58 (0.42, 0.81)*** |
| 6 | Hb at 4–48 h: 1.6 (1.1, 2.1)*** | ND | ||||
| 8 | Hb at 3–6 mo: 0.15 (−0.19, 0.48; P = 0.389) | ND | ||||
| Mothers | 4 | 0.12 (−0.06, 0.31; P = 0.182) | ND | |||
1 *,**,***Significant effect size: *P < 0.05, **P < 0.01, ***P < 0.001. Hb, hemoglobin; IFA, iron-folic acid; IPTp, intermittent preventive treatment in pregnancy; ITN, insecticide-treated nets; MD, mean difference; MNP, micronutrient powder; ND, no data; NS, not significant.