TABLE 2.
The effect of small-quantity LNSs on Hb and micronutrient status1
| Outcomes | Participants (comparisons), n | MD/GMR/PR (95% CI) | P value2 | Heterogeneity I2 (P-heterogeneity)2 | Quality of the evidence (GRADE) |
|---|---|---|---|---|---|
| Hb,3 g/L | 15,398 (14) | 2.77 (2.30, 3.25)4,5 | <0.001 | 0.72 (<0.001) | High |
| Ferritin,3,6 µg/L | 3078 (7) | 1.56 (1.48, 1.64)7 | <0.001 | 0.53 (0.072) | High |
| sTfR,3,6 mg/L | 2480 (6) | 0.83 (0.80, 0.85)7 | <0.001 | 0.46 (0.098) | High |
| ZPP,3,6 µmol/mol heme | 1542 (4) | 0.80 (0.75, 0.85)7 | <0.001 | 0.79 (0.001) | Moderate |
| Plasma zinc,6 µg/dL | 1133 (3) | 1.00 (0.97, 1.02)7 | 0.734 | 0.00 (0.416) | Low |
| Retinol,6 µmol/L | 1236 (4) | 1.04 (1.00, 1.08)7 | 0.057 | 0.08 (0.360) | Moderate |
| RBP,6 µmol/L | 2314 (5) | 1.07 (1.04, 1.09)7 | <0.001 | 0.68 (0.017) | Moderate |
| Anemia (Hb <110 g/L)3 | 15,398 (14) | 0.84 (0.81, 0.87)5,8 | <0.001 | 0.65 (<0.001) | High |
| Moderate-to-severe anemia (Hb <100 g/L)3 | 14,375 (12) | 0.72 (0.68, 0.76)8 | <0.001 | 0.64 (0.001) | High |
| Iron deficiency (ferritin <12 µg/L)3 | 3078 (7) | 0.44 (0.39, 0.50)8 | <0.001 | 0.66 (0.009) | High |
| Iron deficiency anemia (Hb <110 g/L, ferritin <12 µg/L)3 | 2702 (6) | 0.36 (0.30, 0.44)8 | <0.001 | 0.71 (0.004) | High |
| Elevated sTfR (>8.3 mg/L)3 | 2480 (6) | 0.64 (0.59, 0.70)8 | <0.001 | 0.73 (<0.001) | High |
| Elevated ZPP (>70 µmol/mol heme)3 | 1542 (4) | 0.70 (0.61, 0.79)8 | <0.001 | 0.00 (0.881) | Moderate |
| Zinc deficiency (plasma zinc <65 µg/dL) | 537 (2) | — | — | — | — |
| Low vitamin A status (retinol <0.70 µmol/L) | 663 (3) | 1.02 (0.62, 1.69)8 | 0.938 | 0.01 (0.581) | Low |
| Marginal vitamin A status (retinol <1.05 µmol/L) | 1236 (4) | 0.98 (0.85, 1.13)8 | 0.829 | 0.35 (0.206) | Moderate |
| Low vitamin A status (RBP <0.70 µmol/L) | 1790 (3) | 0.44 (0.27, 0.70)8 | 0.001 | 0.00 (0.713) | Moderate |
| Marginal vitamin A status (RBP <1.05 µmol/L) | 2314 (5) | 0.78 (0.70, 0.87)8 | <0.001 | 0.00 (0.765) | Moderate |
GMR, ratio of geometric means; GRADE, Grading of Recommendations Assessment, Development and Evaluation; Hb, hemoglobin; LNS, lipid-based nutrient supplement; MD, mean difference; PR, prevalence ratio; RBP, retinol-binding protein; sTfR, soluble transferrin receptor; ZPP, zinc protoporphyrin.
The P value column corresponds to the pooled main effect 2-sided superiority testing of the intervention effect estimate and 95% CI presented in the preceding column. I2 describes the percentage of variability in effect estimates that may be due to heterogeneity rather than chance. Roughly, 0.3–0.6 may be considered moderate heterogeneity, <0.6 may be considered high heterogeneity. P value from chi-square test for heterogeneity. P < 0.05 indicates statistically significant evidence of heterogeneity of intervention effects beyond chance.
Prespecified as primary outcomes in the statistical analysis plan (22).
MD: LNS − control (95% CI).
The MD for Hb was 2.77 g/L (95% CI: 2.31, 3.23 g/L), and the PR for anemia was 0.83 (0.80, 0.85) when results from the 1 trial that did not participate in the IPD analyses were included (14).
Ferritin, sTfR, ZPP, zinc, retinol, and RBP concentrations were adjusted for inflammation (i.e., C-reactive protein and/or α-1-acid glycoprotein concentrations, as available), using a regression correction approach adapted from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project (29).
GMR: LNS/control (95% CI).
PR: LNS/control (95% CI).