Single variable linear regression 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 | ||||||
|---|---|---|---|---|---|---|
| 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) | |
| *Example: 1.6% increase in diphtheria IgG for each week of gestational age at birth. | ||||||
| †p<0.2; ††p<0.05; †††p<0.01. | ||||||
| FHA, filamentous haemagglutinin; PRN, pertactin; PT, pertussis toxin. | ||||||
| Diphtheria | +1.6†* | +1.0† | +0.68 | +0.82 | −3.2 | −1.0 |
| Tetanus | −1.3 | −0.92 | −15†† | +4.7††† | −6.2† | +4.0 |
| FHA | −0.7 | −0.70 | −13† | +2.4†† | −2.1 | +12.6†† |
| PRN | +0.07 | −0.43 | −27††† | +3.4†† | −2.6 | −2.9 |
| PT | +1.2 | −0.51 | −2.9 | −0.05 | −3.1 | −4.9 |