Table 1

Results from univariate meta-regression and meta-analysis pooled risk ratios for the effect of neonatal vitamin A supplementation against a placebo on mortality (random effects)

Study-level characteristicMortality <6 monthsMortality <12 months
n*Included studies†RR (95% CI)Meta-regression p valuesn*Included studies†RR (95% CI)Meta-regression‡ p values
Overall11a–kRE 0.97 (0.89 to 1.06)10a–h, j, kRE 1.00 (0.93 to 1.08)
Geographic region
 Asia5a, f, i, j, kRE 0.87 (0.77 to 0.98)0.0094a, f, j, kRE 0.91 (0.80 to 1.03)0.013
 Africa6b, c, d, e, g, hRE 1.06 (0.98 to 1.15)6b, c, d, e, g, hRE 1.07 (1.00 to 1.15)
Maternal vitamin A deficiency level
 Moderate/severe3a, f, iRE 0.87 (0.80 to 0.94)0.0122a, fRE 0.91 (0.83 to 1.00)0.033
 None/mild7b, c, d, e, g, h, jRE 1.05 (0.96 to 1.15)7b, c, d, e, g, h, jRE 1.06 (0.98 to 1.15)
Maternal postnatal vitamin A programme
 No7a, d, e, g, i, j, kRE 0.93 (0.82 to 1.05)0.3926a, d, e, g, j, kRE 0.99 (0.88 to 1.12)0.768
 Yes4b, c, f, hRE 1.00 (0.89 to 1.13)4b, c, f, hRE 1.02 (0.91 to 1.13)
Mortality enrolment to 6  months (control group)
 ≥30/10006a, e, f, h, i, kRE 0.91 (0.85 to 0.98)0.0215a, e, f, h, kRE 0.97 (0.89 to 1.04)0.181
 <30/10005b, c, d, g, jRE 1.08 (0.95 to 1.24)5b, c, d, g, jRE 1.06 (0.93 to 1.22)
Ratio of mortality 6–12 months
 ≥75%6a, e, f, h, j, kRE 0.92 (0.84 to 1.01)0.0196a, e, f, h, j, kRE 0.96 (0.86 to 1.06)0.065
 <75%4b, c, d, gRE 1.11 (1.00 to 1.22)4b, c, d, gRE 1.08 (0.99 to 1.17)
Proportion given first DPT by 6  months
 <93%4a, e, I, kRE 0.91 (0.82 to 1.00)0.2093a, e, kRE 0.96 (0.89 to 1.03)0.640
 ≥93%5b, c, d, f, gRE 1.03 (0.91 to 1.18)5b, c, d, f, gRE 1.03 (0.91 to 1.15)
Proportion of mothers with no schooling
 ≥32%4a, f, g, iRE 0.88 (0.80 to 0.96)0.0413a, f, gRE 0.93 (0.85 to 1.01)0.083
 <32%5b, c, d, h, j1.04 (0.92 to 1.18)5b, c, d, h, jRE 1.06 (0.95 to 1.18)
  • *Number of studies included in subgroup analysis.

  • †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 17; (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.

  • ‡P values from univariate meta-regression.

  • DPT, dipropyltryptamine; RE, random effects; RR, rate ratio.