. Author manuscript; available in PMC: 2015 Jun 2.

Published in final edited form as: Psychol Aging. 2008 Dec;23(4):917–927. doi: 10.1037/a0013466

Table 5. Standardized DSS Number Correct over Time as Predicted by Baseline Demographic and Health Variables.

	Model 1		Model 2		Model 3		Model 4

Variable	Estimate	S.E.	Estimate	S.E.	Estimate	S.E.	Estimate	S.E.
Fixed Effects
Intercept	0.080^*	0.037	0.205^**	0.042	0.206^**	0.042	-0.162^**	0.062
Time	0.076^**	0.014	0.087^**	0.015	0.085^**	0.015	0.084^**	0.015
Time²	-0.027^**	0.003	-0.029^**	0.003	0.028^**	0.003	-0.028^**	0.003
Attrition			-0.365^**	0.071	-0.373^**	0.072	-0.186^**	0.064
Attrition*time			-0.045^*	0.019	0.001	0.055	0.001	0.055
Age			-0.054^**	0.006	-0.054^*	0.006	-0.045^**	0.005
Age*time			-0.004^**	0.001	-0.005	0.002	-0.005	0.002
Attrition*time²					-0.016	0.019	-0.016	0.019
Age*time²					-0.001	0.001	-0.001	0.001
CES-D							-0.019^**	0.006
Education							0.051^**	0.012
MMSE							0.089^**	0.016
Gender							0.380^**	0.068
Race							0.468^**	0.066
Self-rated health							-0.161^**	0.036
Visual acuity							0.004	0.003
Random Effects
Residual95% confidence	0.136^**	0.004	0.136^**	0.004	0.136^**	0.004	0.136^**	0.004
Lower	0.128		0.128		0.128		0.128
Upper	0.145		0.145		0.145		0.145
Var (intercept) 95% confidence	0.853^**	0.049	0.706^**	0.041	0.706^**	0.041	0.499^**	0.030
Lower	0.762		0.630		0.630		0.465
Upper	0.956		0.792		0.792		0.590
Var (time) 95% confidence	0.004^**	0.001	0.004^**	0.001	0.004^**	0.001	0.004^**	0.001
Lower	0.003		0.002		0.002		0.002
Upper	0.006		0.006		0.006		0.006
Corr (int, time) 95% confidence	0.015^**	0.093	0.007	0.005	0.007	0.005	0.008^*	0.004
Lower	0.005		-0.002		-0.002		0.001
Upper	0.026		0.016		0.016		0.017
^a Pseudo-R²
Residual	0.137		0.001		< 0.001		-0.001
Intercept	0.037		0.172		< 0.001		0.258
Time			0.152		0.001		< 0.001
Corr (int, time)			0.564		0.003		0.397
Model Fit
Log likelihood	5102.383		4950.521		4949.691		4765.666
AIC	5116.383		4972.521		4975.691		4803.666
BIC	5158.725		5039.058		5054.325		4918.593

p < 0.05, two-tailed.

^**

p < 0.01, two-tailed.

Note. DSS = WAIS-R Digit Symbol Substitution; MMSE = Mini-Mental State Examination; CES-D = Center for Epidemiological Studies – Depression Scale.

Pseudo-R² values for each model are based on the proportion reduction in random variance components above and beyond the model immediately preceding it.