Table 5
Multivariable analysis of influence of gestational age, birth weight, pre-immunisation IgG levels, age at completion of immunisations, and use of antenatal and postnatal steroids on IgG response of preterm infants to vaccine antigens
| Percentage change in IgG titre per unit change in variable p value | ||||||
|---|---|---|---|---|---|---|
| Gestational age (weeks) | Birth weight (100 g) | Pre-immunisation IgG level (IU/ml) | Age at completion (weeks) | Antenatal steroids (number of doses) | Postnatal steroids (number of courses) | |
| Values in parentheses are 95% confidence intervals. | ||||||
| *Example: 2.2% increase in diphtheria IgG for each week of gestational age at birth. | ||||||
| FHA, filamentous haemagglutinin; PRN, pertactin; PT, pertussis toxin. | ||||||
| Diphtheria | +2.2* | +0.7 | −4.5 | +1.1 | −1.8 | +4.8 |
| (−2.5 to +7.0) | (−1.8 to +3.1) | (−16.0 to +7.0) | (−1.7 to +4.0) | (−8.3 to +4.8) | (−11.2 to +20.8) | |
| p = 0.36 | p = 0.58 | p = 0.44 | p = 0.42 | p = 0.59 | p = 0.55 | |
| Tetanus | +7.1 | −2.8 | −18.3 | +5.3 | −9.2 | −2.6 |
| (+1.5 to +12.7) | (−5.6 to +0.04) | (−31.6 to −5.0) | (+2.2 to +12.2) | (−16.8 to −1.7) | (−21.2 to +16.0) | |
| p = 0.014 | p = 0.053 | p = 0.007 | p = 0.001 | p = 0.017 | p = 0.79 | |
| FHA | +5.9 | −2.0 | −17.0 | +2.2 | −5.7 | +10.6 |
| (+0.9 to +10.9) | (−4.5 to +0.49) | (−32.8 to −1.2) | (−0.7 to +5.0) | (−12.6 to +1.1) | (−4.2 to +25.5) | |
| p = 0.02 | p = 0.12 | p = 0.035 | p = 0.14 | p = 0.097 | p = 0.16 | |
| PRN | +7.4 | −0.7 | −36.4 | +5.6 | −3.0 | −4.1 |
| (+1.5 to +13.3) | (−3.7 to +2.2) | (−51.7 to −21.1) | (+2.1 to +9.1) | (−11.3 to +5.3) | (−22.0 to +13.8) | |
| p = 0.015 | p = 0.62 | p<0.001 | p = 0.002 | p = 0.476 | p = 0.65 | |
| PT | +10.6 | −3.4 | −11.3 | +0.9 | −6.8 | +11.2 |
| (+5.2 to 15.9) | (−5.9 to −0.9) | (−25.5 to +3.0) | (−2.1 to +3.9) | (−14.0 to +0.3) | (−4.2 to +26.6) | |
| p<0.001 | p = 0.008 | p = 0.12 | p = 0.56 | p = 0.061 | p = 0.15 | |
