Table II.
Longitudinal Trajectories of Illness Representations: Results of Unconditional Growth Modelsa
| Variable | Fixed effects |
Variance components |
||||
|---|---|---|---|---|---|---|
| b | SE(b) | p | σ2 | SE | p | |
| Chronicity | ||||||
| Intercept | 3.97 | 0.04 | <.01 | 0.30 | 0.04 | <.01 |
| Slope (age)b | 0.06 | 0.02 | .01 | not estimated | ||
| Cyclicality | ||||||
| Intercept | 2.79 | 0.05 | <.01 | 0.36 | 0.07 | <.01 |
| Slope (age) | −0.07 | 0.03 | .02 | 0.02 | 0.02 | .40 |
| Consequences | ||||||
| Intercept | 3.23 | 0.05 | <.01 | 0.28 | 0.05 | <.01 |
| Slope (age) | 0.06 | 0.03 | .02 | 0.02 | 0.01 | .14 |
| Personal control | ||||||
| Intercept | 4.12 | 0.03 | <.01 | 0.18 | 0.02 | <.01 |
| Slope (age)b | 0.11 | 0.02 | <.01 | not estimated | ||
| Parent control | ||||||
| Intercept | 3.05 | 0.04 | <.01 | 0.21 | 0.04 | <.01 |
| Slope (age) | −0.06 | 0.02 | .00 | 0.00 | 0.01 | .83 |
| Treatment control | ||||||
| Intercept | 3.73 | 0.04 | <.01 | 0.13 | 0.03 | <.01 |
| Slope (age) | 0.04 | 0.02 | .05 | 0.02 | 0.01 | .04 |
| Coherence | ||||||
| Intercept | 4.02 | 0.05 | <.01 | 0.29 | 0.05 | <.01 |
| Slope (age) | 0.09 | 0.03 | <.01 | 0.02 | 0.02 | .25 |
| Emotional representations | ||||||
| Intercept | 2.43 | 0.06 | <.01 | 0.52 | 0.08 | <.01 |
| Slope (age) | −0.03 | 0.03 | .37 | 0.03 | 0.02 | .22 |
Note. aAge, centered at 13 years, was the marker of time (slope).
bThe initial model estimated negative variance in the slope, indicating variability in slopes was close to 0. The final model did not include a variance component for slope.