Individual-level characteristic | Mortality <6 months | Mortality <12 months | ||||||||
Studies (n) | Included studies* | RR (95% CI) | I2 (p values) | P values of test of heterogeneity | Studies (n) | Included studies* | RR (95% CI) | I2 (p values) | P values of test of heterogeneity | |
Overall | 11 | a–k | 0.97 (0.89 to 1.06) | 49.4 (0.03) | 10 | a–h, j, k | 1.00 (0.93 to 1.08) | 46.3 (0.05) | ||
Sex | ||||||||||
Male | 11 | a–k | 0.99 (0.92 to 1.08) | 49.0 (0.03) | 0.255 | 10 | a–h, j, k | 1.00 (0.93 to 1.07) | 46.6 (0.05) | 0.760 |
Female | 0.93 (0.86 to 1.01) | 26.5 (0.19) | 0.99 (0.92 to 1.06) | 42.8 (0.07) | ||||||
Birth weight (g) | ||||||||||
<2500 | 8 | a, b, c, f, h, i, j, k | 0.97 (0.89 to 1.05) | 52.0 (0.04) | 0.895 | 7 | a, b, c, f, h, j, k | 0.99 (0.92 to 1.08) | 36.9 (0.15) | 0.964 |
≥2500 | 0.96 (0.89 to 1.04) | 44.8 (0.08) | 1.00 (0.93 to 1.07) | 34.6 (0.16) | ||||||
Size for gestation age | ||||||||||
Preterm SGA | 6 | a, c, f, h, i, j | 1.09 (0.86 to 1.39) | 29.6 (0.21) | 0.294 | 5 | a, c, f, h, j | 1.14 (0.90 to 1.45) | 4.1 (0.38) | 0.354 |
Preterm AGA | 0.94 (0.81 to 1.08) | 27.7 (0.24) | 0.95 (0.83 to 1.09) | 0.0 (0.54) | ||||||
Term SGA | 0.87 (0.78 to 0.97) | 21.1 (0.28) | 0.92 (0.83 to 1.02) | 3.6 (0.39) | ||||||
Term AGA | 0.98 (0.87 to 1.10) | 0.0 (0.88) | 1.00 (0.91 to 1.10) | 0.0 (0.95) | ||||||
Age at dosing (hours) | ||||||||||
<24 | 11 | a–k | 0.99 (0.92 to 1.06) | 31.6 (0.15) | 0.594 | 10 | a–h, j, k | 0.99 (0.93 to 1.05) | 25.2 (0.21) | 0.682 |
24–47 | 0.93 (0.83 to 1.04) | 32.0 (0.14) | 1.03 (0.93 to 1.14) | 28.0 (0.19) | ||||||
≥48 | 0.93 (0.77 to 1.12) | 0.0 (0.75) | 0.94 (0.79 to 1.12) | 0.0 (0.94) | ||||||
Parity | ||||||||||
1 child | 11 | a–k | 0.91 (0.83 to 1.00) | 13.3 (0.32) | 0.338 | 10 | a–h, j, k | 0.96 (0.88 to 1.04) | 0.0 (0.46) | 0.308 |
2–3 children | 1.00 (0.92 to 1.09) | 0.0 (0.64) | 1.05 (0.97 to 1.13) | 3.5 (0.41) | ||||||
≥4 children | 0.97 (0.86 to 1.09) | 44.9 (0.05) | 0.98 (0.89 to 1.09) | 48.4 (0.04) | ||||||
Maternal schooling | ||||||||||
None | 9 | a–i | 0.95 (0.86 to 1.05) | 53.4 (0.03) | 0.782 | 8 | a–h | 0.96 (0.88 to 1.05) | 43.7 (0.09) | 0.611 |
Primary school | 0.98 (0.88 to 1.09) | 6.2 (0.38) | 1.02 (0.93 to 1.11) | 0.0 (0.73) | ||||||
Secondary school or more | 0.93 (0.85 to 1.02) | 16.9 (0.29) | 1.00 (0.92 to 1.09) | 53.2 (0.03) | ||||||
Time of breast feeding initiation (hours) | ||||||||||
≤1 | 6 | a, b, c, f, h, k | 1.03 (0.94 to 1.14) | 63.2 (0.02) | 0.339 | 6 | a, b, c, f, h, k | 1.03 (0.95 to 1.12) | 55.8 (0.04) | 0.313 |
2–23 | 0.94 (0.87 to 1.03) | 0.0 (0.71) | 0.97 (0.90 to 1.05) | 0.0 (0.65) | ||||||
≥24 | 0.92 (0.74 to 1.13) | 0.0 (0.67) | 0.90 (0.74 to 1.08) | 0.0 (0.69) | ||||||
Colostrum given | ||||||||||
Yes | 7 | a, b, c, f, h, i, k | 0.96 (0.90 to 1.0) | 47.2 (0.08) | 0.974 | 6 | a, b, c, f, h, k | 1.00 (0.94 to 1.05) | 35.4 (0.17) | 0.860 |
No | 0.96 (0.82 to 1.13) | 0.0 (0.47) | 0.98 (0.84 to 1.14) | 0.0 (0.52) | ||||||
Maternal vitamin A supplementation | ||||||||||
Yes | 4 | b, c, f, h | 0.97 (0.88 to 1.08) | 58.8 (0.06) | 0.273 | 4 | b, c, f, h | 1.00 (0.92 to 1.09) | 62.3 (0.05) | 0.505 |
No | 1.06 (0.94 to 1.19) | 27.2 (0.25) | 1.05 (0.95 to 1.16) | 72.2 (0.01) | ||||||
Maternal night blindness | ||||||||||
Yes | 3 | f, i, k | 0.93 (0.65 to 1.33) | 0.0 (0.49) | 0.660 | 2 | f, k | 0.94 (0.64 to 1.37) | 30.0 (0.23) | 0.765 |
No | 0.86 (0.77 to 0.96) | 58.3 (0.09) | 0.88 (0.78 to 1.00) | 70.8 (0.06) | ||||||
Maternal serum retinol level (μmol/L) | ||||||||||
<1.05 | 3 | a, f, h | 0.73 (0.51 to 1.05) | 0.0 (0.51) | 0.042 | 3 | a, f, h | 0.82 (0.60 to 1.13) | 0.0 (0.54) | 0.067 |
≥1.05 | 1.26 (0.86 to 1.84) | 0.0 (0.84) | 1.26 (0.90 to 1.77) | 0.0 (0.75) |
↵*Studies are noted as follows: (a) Mazumder et al 22; (b) Edmond et al 24; (c) Masanja et al 23; (d) Benn et al 19; (e) Benn et al ; (f) Klemm et al 13; (g) Benn et al 18; (h) Malaba et al 16 and Humphrey et al 15; (i) Rahmathullah et al 14; (j) Humphrey et al 12; (k) Soofi et al 25 .
AGA, appropriate for gestational age; RR, rate ratio; SGA, small for gestational age.