Table 3. Multi-level modelling: factors associated with growth trajectories within EP participants a .
| Variables | Height z-score (Unadjusted) | Height z-score (Adjusted b) (n=277) |
||
|---|---|---|---|---|
| Estimate (95% CI) | p | Estimate (95% CI) | p | |
| Gestational age (per week) | 0.05 (-0.11,0.21) [n=287] | 0.546 | - | - |
| Moderate-severe brain injury (ref.=minor/none) | -0.26 (-0.54,0.02) [n=286] | 0.068 | - | - |
| Birthweight z-score (per SD) | 0.28 (0.13,0.43) [n=284] | <0.001 | 0.27 (0.13,0.41) | <0.001 |
| White ethnicity (ref.=other ethnicities) | -0.65 (-0.94,-0.37) [n=287] | <0.001 | -0.65 (-0.92,-0.38) | <0.001 |
| Ethnicity*Agec | 0.02 (0.00,0.05) [n=287] | 0.041 | 0.03 (0.01,0.05) | 0.007 |
| Enteral feeding begun before day 7 (ref.=no) | 0.33 (0.09,0.56) [n=279] | 0.006 | 0.35 (0.13,0.57) | 0.002 |
| Enteral feeding*Agec | -0.02 (-0.04,-0.00) [n=279] | 0.017 | -0.02 (-0.04,-0.00) | 0.011 |
| Steroids for chronic lung disease (per week) | -0.03 (-0.07,0.01) [n=282] | 0.133 | - | - |
|
| ||||
| Weight z-score (Unadjusted) |
Weight z-score (Adjusted b)
(n=280) |
|||
| Estimate (95% CI) | p | Estimate (95% CI) | p | |
|
| ||||
| Gestational age (per week) | -0.01 (-0.20,0.18) [n=290] | 0.919 | - | - |
| Moderate-severe brain injury (ref.=minor/none) | -0.15 (-0.47,0.17) [n=289] | 0.363 | - | - |
| Birthweight z-score (per SD) | 0.29 (0.12,0.17) [n=287] | 0.001 | 0.28 (0.11,0.45) | 0.001 |
| Birthweight z-score*Agec | -0.03 (-0.04,-0.01) [n=287] | 0.005 | -0.03 (-0.05,-0.01) | 0.003 |
| White ethnicity (ref.= other ethnicities) | -0.63 (-0.95,-0.30) [n=290] | <0.001 | -0.63 (-0.95,-0.32) | <0.001 |
| Ethnicity*Agec | 0.04 (0.00,0.07) [n=290] | 0.030 | 0.04 (0.01,0.08) | 0.015 |
| Enteral feeding begun before day 7 (ref.=no) | 0.42 (0.15,0.68) [n=282] | 0.002 | 0.45 (0.19,0.70) | 0.001 |
| Steroids for chronic lung disease (per week) | -0.03 (-0.07,0.01) [n=285] | 0.141 | - | - |
|
| ||||
| BMI z-score (Unadjusted) |
BMI z-score (Adjusted b)
(n=276) |
|||
| Estimate (95% CI) | p | Estimate (95% CI) | p | |
|
| ||||
| Gestational age (per week) | -0.02 (-0.20,0.16) [n=286] | 0.813 | - | - |
| Moderate-severe brain injury (ref.=minor/none) | -0.01 (-0.32,0.31) [n=285] | 0.970 | - | - |
| Birthweight z-score (per SD) | 0.13 (-0.04,0.30) [n=283] | 0.144 | 0.13 (-0.04,0.31) | 0.133 |
| Birthweight z-score*Agec | -0.02 (-0.04,-0.00) [n=283] | 0.017 | -0.03 (-0.05,-0.01) | 0.014 |
| White ethnicity (ref.= other ethnicities) | -0.13 (-0.44,0.19) [n=286] | 0.432 | - | - |
| Enteral feeding begun before day 7 (ref.=no) | 0.30 (0.03,0.56) [n=278] | 0.026 | 0.29 (0.03,0.56) | 0.028 |
| Steroids for chronic lung disease (per week) | -0.01 (-0.05,0.03) [n=281] | 0.708 | - | - |
|
| ||||
| Head circumference z-score (Unadjusted) |
Head circumference z-score (Adjusted b)
(n=276) |
|||
| Estimate (95% CI) | p | Estimate (95% CI) | p | |
|
| ||||
| Gestational age (per week) | 0.25 (0.05,0.44) [n=290] | 0.013 | 0.46 (0.25,0.67) | <0.001 |
| Moderate-severe brain injury (ref.=minor/none) | -0.19 (-0.53,0.16) [n=289] | 0.289 | - | - |
| Birthweight z-score (per SD) | 0.31 (0.13,0.49) [n=287] | 0.001 | 0.38 (0.19,0.56) | <0.001 |
| White ethnicity (ref.= other ethnicities) | 0.13 (-0.22,0.48) [n=290] | 0.467 | - | - |
| Enteral feeding begun before day 7 (ref.=no) | 0.38 (0.09,0.66) [n=282] | 0.009 | 0.30 (0.02,0.57) | 0.033 |
| Steroids for chronic lung disease (per week) | -0.05 (-0.10,-0.01) [n=285] | 0.020 | -0.04 (-0.08,0.00) | 0.079 |
a
For all models, age was centred at 6 years to make intercept coefficients more meaningful. One variable each time in the unadjusted models. For continuous variables (e.g., birthweight z-score), estimate refers to estimated change in growth measure z-scores for per unit change in the predictor. For categorical variables, it refers to estimated difference in means relative to the reference group.
b
Adjusted for age and variables with a p value <0.05 in the unadjusted models.
c
Interactions with age at assessment were shown if significant. Significant interactions indicate that the impact of the predictor on the growth outcomes differed with age at assessment.