Table 1.
The univariate analysis of the association between pertussis-like illness, maternal vaccination and potential confounders in infants aged under six months born in the Metropolitan Region of Recife from July 2016 to July 2018.
| Variables | Odds ratio | (CI 95%) | p-Valuea |
|---|---|---|---|
| Mothers | |||
| Maternal vaccination (Tdap) | |||
| Vaccinated | 1 | ||
| Unvaccinated | 0.73 | (0.404 1.34) | 0.31 |
| Mother’s age | |||
| ≤ 18 years | 1 | ||
| 18 to 35 years | 1.09 | (0.50, 2.38) | 0.8 |
| ≥ 36 years | 0.82 | (0,18, 3.80) | 0.82 |
| Prenatal care | |||
| 7 or more visits | 1 | ||
| 4 to 6 visits | 0.75 | (0.32, 2.32) | 0.34 |
| 0 to 3 visits | 0.87 | (0.41, 1.36) | 0.78 |
| Type of delivery | |||
| Normal | 1 | ||
| C-section | 1.81 | (0.98, 3.37) | 0.05 |
| Schooling | |||
| Primary school | 1 | ||
| Secondary school | 1.27 | (0.68, 2.36) | 0.44 |
| Higher education | 1.21 | (0.31, 4.74) | 0.77 |
| Urban cities | |||
| Recife | 1 | ||
| Jaboatão | 1.27 | (0.58, 2.80) | 0.54 |
| Cabo | 1.06 | (0.33, 3.37) | 0.91 |
| Others | 0.92 | (0.39, 2,16) | 0.86 |
| Infants | |||
| Sex of infant | |||
| Female | 1 | ||
| Male | 1.56 | (0.90, 2.72) | 0.11 |
| Birth weight | |||
| >2500 | 1 | ||
| <2500 | 1.71 | (0.69, 4.21) | 0.23 |
| Gestational age at birth | |||
| Term (≥37 weeks and <42 weeks) | 1 | ||
| Pre-term (< 37 weeks) | 5.412 | (1.48, 19.67) | 0.01 |
| Post-term (≥42 weeks) | 4.426 | (0.93, 20.99) | 0.06 |
| Infant vaccination (DTP) | |||
| Unvaccinated | 1 | ||
| Vaccinated | 0.265 | (0.064, 1.09) | 0.06 |
| Breastfeeding | |||
| <6 months | 1 | ||
| Exclusive for 6 months | 0.26 | (0.11, 062) | 0.002 |
| Mothers and infants | |||
| 1. Unvaccinated and breastfed < 6 months | 1 | ||
| 2. Unvaccinated and exclusively breastfed for 6 months | 0.27 | (0.07, 1.00) | 0.05 |
| 3. Vaccinated and breastfed < 6 months | 0.8 | (0.24, 2.65) | 0.72 |
| 4. Vaccinated and exclusively breastfed for 6 months | 0.21 | (0.06, 0.69) | 0.01 |
CI, confidence interval.
a
X2 Chi-square or Fisher’s tests.