Maternal multiple micronutrient supplementation and pregnancy outcomes in developing countries: meta-analysis and meta-regression
Kosuke Kawai, Donna Spiegelman, Anuraj H Shankar & Wafaie W Fawzi
Volume 89, Number 6, June 2011, 402-411B
Table 5. Subgroup analysis and meta-regression for the effect of maternal multiple micronutrient supplements on the risk of small size for gestational age in developing countries
| Characteristic | No. of trials | Pooled RR (95% CI) | Univariate meta-regression |
||
|---|---|---|---|---|---|
| P-value for test for heterogeneity by covariate | Residual I2 after adjusting for covariate (P-value) | Reduction in I2 after adjusting for covariate (%) | |||
| Average gestational age at initiation of supplements | 0.12 | 9% (0.35) | 81 | ||
| < 20 weeks | 9 | 0.95 (0.89–1.02) | – | – | – |
| ≥ 20 weeks | 6 | 0.77 (0.65–0.91) | – | – | – |
| No maternal education | 0.22 | 29% (0.16) | 34 | ||
| < 50% | 9 | 0.84 (0.76–0.92) | – | – | – |
| ≥ 50% | 4 | 0.95 (0.84–1.08) | – | – | – |
| Iron dose in treatment and control groups | 0.86 | 47% (0.02) | 0 | ||
| Same | 7 | 0.82 (0.70–0.97) | – | – | – |
| Different | 8 | 0.85 (0.67–1.08) | – | – | – |
| Maternal underweighta | 0.47 | 34% (0.04) | 28 | ||
| < 20% | 11 | 0.85 (0.78–0.91) | – | – | – |
| ≥ 20% | 4 | 0.96 (0.82–1.14) | – | – | – |
| Average maternal height | 0.21 | 34% (0.10) | 28 | ||
| < 155 cm | 7 | 0.98 (0.91–1.06) | – | – | – |
| ≥ 155 cm | 8 | 0.80 (0.73–0.89) | – | – | – |
| Primiparas | 0.54 | 47% (0.02) | 0 | ||
| < 35% | 8 | 0.82 (0.70–0.97) | – | – | – |
| ≥ 35% | 7 | 0.85 (0.79–0.92) | – | – | – |
CI, confidence interval; RR, relative risk.
a Body mass index (weight in kg divided by square of height in metres) < 18.5.