Cortisol reactivity to vaccination
| Birth group | Cortisol reactivity to vaccine Mean±SD | Estimated group differences in cortisol reactivity (95% CI) | P value |
| Birth group comparisons | |||
| Term (≥37 weeks), n=45 | 13.1±11.9 | Reference | |
| Preterm (≤32 weeks), n=56 | 9.3±10.2 | −3.9 (−8.3 to 0.5) | 0.09 |
| Extremely preterm (<28 weeks), n=14 | 5.8±8.5 | −7.3 (−14.0 to −0.6) | 0.03 |
| Very preterm (28–32 weeks), n=42 | 10.4±10.6 | −2.7 (−7.4 to 2.0) | 0.26 |
| Birth group comparisons stratified by sex | |||
| Male term (≥37 weeks), n=21 | 14.5±11.7 | Reference | |
| Male preterm (≤32 weeks), n=38 | 6.8±8.7 | −7.7 (−13.4 to −2.0) | 0.009 |
| Female term (≥37 weeks), n=24 | 11.9±12.2 | Reference | |
| Female preterm (≤32 weeks), n=18 | 14.5±11.5 | 2.5 (−4.5 to 9.6) | 0.47 |
Cortisol reactivity was calculated by subtracting the prevaccine cortisol concentration from the postvaccine cortisol concentration.
Effect sizes represent cortisol concentrations in nmol/L.