Table 1.
Individual growth models for longitudinal changes in physical healtha
| Unconditional Linear Model | Unconditional Non-linear Model | Gender | Psychiatric Disorder | |
| Estimate (SE) | Estimate (SE) | Estimate (SE) | Estimate (SE) | |
| Random Variance | ||||
| Intercept | 101.53 (8.14) *** | 101.68 (8.11) *** | 87.34 (7.39) *** | 79.86 (7.09) *** |
| Linear Slope | 0.30 (0.08) *** | 0.31 (0.08) *** | 0.30 (0.08) *** | 0.28 (0.08) *** |
| Residual | 130.45 (7.17) *** | 129.36 (7.12) *** | 128.50 (6.96) *** | 128.71 (7.04) *** |
| Fixed Effects | ||||
| Intercept | 74.71 (0.44) *** | 75.19 (0.52) *** | 70.95 (0.59) *** | 72.26 (0.60) *** |
| Age | -0.63 (0.04) *** | -0.59 (0.05) *** | -0.73 (0.06) *** | -0.67 (0.06) *** |
| Age2 | -0.01 (0.01) | -- | -- | |
| Gender | 7.61 (0.84) *** | 7.24 (0.81) *** | ||
| Gender × Age | 0.25 (0.08) ** | 0.22 (0.08) ** | ||
| Psychiatric Disorder | -5.95 (0.87) *** | |||
| Psychiatric Disorder × Age | -0.23 (0.11) * | |||
| Goodness of Fitb | ||||
| Parameters | 5 | 6 | 7 | 9 |
| Raw Likelihood (-2LL) | 17624.0 | 17627.0 | 17538.3 | 17485.8 |
| X2 | 3.0 | 85.7 *** | 138.2*** | |
| Degrees of Freedom | 1 | 2 | 4 | |
Note. SE = standard error; LL = log likelihood.
aAll parameter entries are maximum likelihood estimates fitted using SAS PROC MIXED.
Age was centered at 23 years, Gender was coded 0 = Female, 1 = Male.
Psychiatric disorder was coded 0 = no disorder, 1= disorder.
bModels for non-linear, gender and psychiatric disorder are compared with the unconditional linear growth model.
* p < 0.05; ** p < 0.01; *** p < 0.001