Table 4.
The adjusted effect of Vitamin A Supplementation on Infant Mortality, stratified by DTP Vaccination and Infant Sex, from 30 to 365 days.
|
Vitamin A |
Placebo |
HR (95% CI) for Mortalitya | P-value for DTP-Vitamin A Interactionb | ||||
|---|---|---|---|---|---|---|---|
| Number of deaths | Number of infant months | Number of deaths | Number of infant months | ||||
| Ghana | |||||||
| Overall Population | Unvaccinated Time (DTP) | 31 | 12,327 | 38 | 12,533 | 0.87 (0.54–1.41) | 0.18 |
| Vaccinated Time (DTP) | 165 | 109,301 | 133 | 109,707 | 1.26 (1.00–1.58) | ||
| Female Infants | Unvaccinated Time (DTP) | 13 | 5,898 | 19 | 6,224 | 0.75 (0.37–1.52) | 0.26 |
| Vaccinated Time (DTP) | 79 | 53,589 | 70 | 54,526 | 1.16 (0.84–1.60) | ||
| Male Infants | Unvaccinated Time (DTP) | 18 | 6,430 | 19 | 6,309 | 1.00 (0.52–1.92) | 0.38 |
| Vaccinated Time (DTP) | 86 | 55,712 | 63 | 55,181 | 1.38 (0.99–1.91) | ||
| Tanzania | |||||||
| Overall Population | Unvaccinated Time (DTP) | 123 | 17,100 | 111 | 16,966 | 1.10 (0.85–1.42) | 0.80 |
| Vaccinated Time (DTP) | 205 | 141,196 | 197 | 141,513 | 1.05 (0.87–1.28) | ||
| Female Infants | Unvaccinated Time (DTP) | 54 | 8,157 | 45 | 8,113 | 1.19 (0.80–1.77) | 0.78 |
| Vaccinated Time (DTP) | 103 | 66,783 | 83 | 67,665 | 1.27 (0.95–1.70) | ||
| Male Infants | Unvaccinated Time (DTP) | 69 | 8,943 | 66 | 8,840 | 1.04 (0.74–1.46) | 0.50 |
| Vaccinated Time (DTP) | 102 | 74,391 | 114 | 73,838 | 0.89 (0.68–1.17) | ||
All hazard ratios are calculated using Cox proportional hazards models allowing for time-varying vaccination status and controlling for continuous birthweight (with spline knots at 1.5, 2, 2.5, and 3.5 kg), head of household (mother, father, grandmother, grandfather, other), household religion (Christian, Muslim, None, Traditional African), maternal age (<20, 20–24, 25–29, 30–34, 35–39, ≥40), maternal education (None, Primary, Secondary for Tanzania, and additionally Post-secondary for Ghana), multiple or singleton birth, number of living children in household (0, 1, 2, 3 + ), number of children in household who have died (0, 1, 2, 3 + ), place of birth (Home, Facility, Other), site ID (1–4 for Ghana and 1–2 for Tanzania), wealth quintile, delivery type (vaginal or caesarean), and maternal megadose of vitamin A.
Three-way interaction between Vitamin A status, DTP vaccination, and sex was not significant (Ghana: p = 0.83, Tanzania: p = 0.53).