Table 4.
Mediation analysis of the indirect effects and total effects of preterm status on the total PedsQL GCS score (four categories of gestational age: < 26 weeks, 26–27 weeks; 28–29 weeks; 30–31 weeks (referent))
| Coef (SE) | Bootstrap 95% confidence interval | ||
|---|---|---|---|
| < 26 | BPD: indirect effectsa | − 1.73 (0.49) | (− 2.68, − 0.77) |
| Direct effectsb | − 1.06 (1.18) | (− 3.38, 1.26) | |
| BPD: total effectsc | − 2.79 (1.16) | (− 5.06, − 0.51) | |
| Severe non-respiratory morbidity: indirect effectsa | − 17.56 (3.37) | (− 24.15, − 10.96) | |
| Direct effectsb | − 1.06 (1.18) | (− 3.38, 1.26) | |
| Severe non-respiratory morbidity: total effectsc | − 18.62 (3.29) | (− 25.06, − 12.17) | |
| 26–27 | BPD: indirect effectsa | − 0.99 (0.27) | (− 1.53, − 0.46) |
| Direct effectsb | 0.10 (0.75) | (− 1.37, 1.57) | |
| BPD: total effectsc | − 0.90 (0.75) | (− 2.37, 0.58) | |
| Severe non-respiratory morbidity: indirect effectsa | − 10.95 (2.16) | (− 15.19, − 6.70) | |
| Direct effectsb | 0.10 (0.75) | (− 1.37, 1.57) | |
| Severe non-respiratory morbidity: total effectsc | − 10.85 (2.17) | (− 15.09, − 6.60) | |
| 28–29 | BPD: indirect effectsa | − 0.34 (0.10) | (− 0.54, − 0.15) |
| Direct effectsb | − 0.45 (0.65) | (− 1.73, 0.82) | |
| BPD: total effectsc | − 0.80 (0.65) | (− 2.08, 0.49) | |
| Severe non-respiratory morbidity: indirect effectsa | − 4.80 (1.10) | (− 6.96, − 2.64) | |
| Direct effectsb | − 0.45 (0.65) | (− 1.73, 0.82) | |
| Severe non-respiratory morbidity: total effectsc | − 5.25 (1.24) | (− 7.68, − 2.82) |
This was performed based on 1000 bootstrap simulations
aThis presents the indirect effect of each mediator (BPD and Severe non-respiratory morbidity) on the PedsQL GCS score. See Fig. 1
bThis represents the direct effect of gestational age (GA) on the PedsQL GCS score. See Fig. 1
cTotal effects are calculated as the sum of the direct effects and indirect effects that are the product of path coefficients (e.g. preterm birth to BPD * BPD to PedsQL GCS score)