Table 6.
Results of GEE multivariable analysis with parameter estimates, standard errors and Wald Chi square for the cohort for the dependent variable cognitive level.
| Wald | ||||
|---|---|---|---|---|
| Variable | B | SE | Chi-square | P-value |
| Model 1 with SGA | ||||
| SGA | 0.82 | 0.76 | 1.2 | 0.28 |
| Sex = female | 2.51 | 0.91 | 7.51 | 0.006 |
| Time = 18 months | -0.70 | 0.42 | 2.81 | 0.09 |
| Time = 5 years | 1.88 | 0.49 | 15.0 | <0.001 |
| Model 2 with IVH | ||||
| IVH = 0 | 1.6 | 1.08 | 2.12 | 0.14 |
| IVH = 1 | 3.6 | 1.07 | 11.2 | 0.001 |
| Sex = female | 2.76 | 1.00 | 7.6 | 0.006 |
| Time = 18 months | -0.75 | 0.47 | 2.5 | 0.11 |
| Time = 5 years | 2.01 | 0.52 | 14.7 | <0.001 |
| Model 3∗ Maternal education | ||||
| University | 5.1 | 1.26 | 16.4 | <0.001 |
| Bachelor/masters | 3.6 | 0.97 | 13.8 | <0.001 |
| Diploma | 1.9 | 0.68 | 7.81 | 0.005 |
| Elementary | 1.5 | 0.90 | 2.8 | 0.094 |
| Sex = female | 2.68 | 0.96 | 7.77 | 0.005 |
| Time = 18 months | -0.77 | 0.45 | 2.86 | 0.09 |
| Time = 5 years | 1.51 | 0.84 | 3.21 | 0.07 |
| Model 4∗ Paternal Education | ||||
| University | 4.51 | 1.22 | 12.1 | <0.001 |
| Bachelor/Masters | 1.93 | 0.95 | 4.0 | 0.047 |
| Diploma | 2.43 | 1.25 | 3.78 | |
| High school | 2.60 | 0.72 | 13.4 | <0.001 |
| Elementary | 1.74 | 0.78 | 4.91 | 0.027 |
| Sex = female | 2.53 | 1.26 | 3.93 | 0.047 |
| Time = 18 months | -0.78 | 0.48 | 2.71 | 0.10 |
| Time = 5 years | 2.04 | 0.54 | 14.3 | <0.001 |
| Model 5 Respiratory support# | ||||
| Level = 0 | 3.15 | 1.25 | 6.3 | 0.012 |
| Level = 1 | 2.35 | 1.25 | 3.5 | 0.06 |
∗Reference: less than elementary; #Reference: respiratory support = level 2. The multivariable models include the variables sex and time with the interaction.