. Author manuscript; available in PMC: 2010 Mar 24.

Published in final edited form as: Psychol Assess. 2008 Sep;20(3):206–216. doi: 10.1037/a0012764

Table 8. DSM-IV Generalized Anxiety Disorder Item-by-Item Tests for Effects of Age on Factor Loadings.

Model	−2LnL	Δχ²	Δdf	AIC	Age effect
Age on latent variance (baseline)	14,246.04			−14,567.96
Item free
Did your muscles often feel tense, sore or achy?	14,245.99	0.05	1	−14,566.01	.03
Did you often tire easily?	14,235.09	10.95^**	1	−14,576.91	.38
Were you so nervous you had trouble concentrating?	14,245.52	0.52	1	−14,566.48	.08
Did you often have trouble falling asleep?	14,246.02	0.02	1	−14,565.98	.01
Were you often irritable or especially impatient?	14,227.90	18.13^***	1	−14,584.10	−.47
Did you feel restless or keyed up and on edge?	14,245.97	0.07	1	−14,566.03	.03

Note. N = 6,426. The most parsimonious model is shown in boldface. AIC = Akaike information criterion.

^**

p < .01.

^***

p < .001.