. Author manuscript; available in PMC: 2013 Feb 18.

Published in final edited form as: Psychol Aging. 2011 Sep;26(3):546–558. doi: 10.1037/a0023023

Table 2.

Goodness-of-Fit Model Comparison Among Alternative Bivariate Dual Change Score Models of Memory and Functional Limitations over Chronological Age in the AHEAD Study

Model	χ²	df	Δ χ²/df	CFI	RMSEA
	Zero-order model
Bidirectional
Full Coupling	2,401.01	1,100	–	.947	.013
Equal Coupling	3,203.44	1,101	802.43 (1)^*	.914	.017
No direction
No Coupling	3,281.25	1,102	880.24 (2)^*	.911	.017
Unidirectional
Coupling γmemory → FL = 0	3,280.83	1,101	879.82 (1)^*	.911	.017
Coupling γFL → memory = 0	2,613.88	1,101	212.87 (1)^*	.938	.014
	Gender, education, health conditions, and depressive symptoms included
Bidirectional
Full Coupling	2,709.70	1,292	–	.948	.013
Equal Coupling	3,556.85	1,293	847.15 (1)^*	.918	.016
No direction
No Coupling	3,637.95	1,294	928.25 (2)^*	.915	.016
Unidirectional
Coupling γmemory → FL = 0	3,636.99	1,293	927.29 (1)^*	.915	.016
Coupling γFL → memory = 0	2,947.12	1,293	237.42 (1)^*	.940	.014

Note. N = 6,990. FL = Functional Limitations. CFI = Comparative Fit Index. RMSEA = Root Mean Square Error of Approximation.

p < .01.