TABLE 4:
Age-related change in brain volume in 83 patients with SCD and 43 control subjects
| Effect | Estimate* | Standard Error | P Value† |
|---|---|---|---|
| Total brain volume | |||
| Intercept for controls | 99.34 | 3.36 | <.0001 |
| Intercept for SCD | 89.93 | 2.12 | <.0001 |
| Age × controls | −0.21 | 0.32 | NS |
| Age × SCD patients | 0.51 | 0.21 | .0162 |
| White matter | |||
| Intercept for controls | 25.74 | 2.00 | <.0001 |
| Intercept for SCD | 23.06 | 1.27 | <.0001 |
| Age × controls | 0.18 | 0.19 | NS |
| Age × SCD patients | 0.44 | 0.13 | .0007 |
| Gray matter | |||
| Intercept for controls | 70.95 | 2.59 | <.0001 |
| Intercept for SCD | 60.81 | 1.63 | <.0001 |
| Age × controls | −0.69 | 0.24 | .0050 |
| Age × SCD patients | 0.05 | 0.16 | NS |
| Central gray matter | |||
| Intercept for controls | 12.64 | 0.66 | <.0001 |
| Intercept for SCD | 10.41 | 0.42 | <.0001 |
| Age × controls | −0.13 | 0.06 | .0360 |
| Age × SCD patients | 0.02 | 0.04 | NS |
| Cortical gray matter | |||
| Intercept for controls | 58.49 | 1.98 | <.0001 |
| Intercept for SCD | 51.66 | 1.25 | <.0001 |
| Age × controls | −0.59 | 0.19 | .0019 |
| Age × SCD patients | −0.07 | 0.12 | NS |
| CSF | |||
| Intercept for controls | 2.65 | 1.05 | .0130 |
| Intercept for SCD | 6.05 | 0.66 | <.0001 |
| Age × controls | 0.31 | 0.10 | .0024 |
| Age × SCD patients | 0.02 | 0.07 | NS |
*
Estimates of fitted model between groups.
†
The P value for the “Intercept for controls” and the “Intercept for SCD” tests whether the respective intercept is significantly different from zero. The P value for “Age × controls” and “Age × SCD patients” tests whether there is a significant effect of age in controls and patients, respectively, by testing whether the slope is significantly different from zero slope.