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.