. 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 9. DSM–IV Generalized Anxiety Disorder Item-by-Item Tests for Effects of Study on Factor Loadings.

Model	−2LnL	Δχ²	Δdf	AIC	Study effect
Study on latent variance (baseline)	14,241.95			−14,572.04
Item free
Did your muscles often feel tense, sore or achy?	14,238.55	3.32	1	−14,573.45	−0.10
Did you often tire easily?	14,233.45	8.42^**	1	−14,578.55	0.16
Were you so nervous you had trouble concentrating?	14,229.69	12.18^***	1	−14,582.31	0.17
Did you often have trouble falling asleep?	14,240.13	1.74	1	−14,571.87	0.07
Were you often irritable or especially impatient?	14,224.63	17.24^***	1	−14,587.37	−0.21
Did you feel restless or keyed up and on edge?	14,237.78	4.09^*	1	−14,574.22	−0.11

Note. N = 6,426. The most parsimonious model is shown in boldface. DSM–IV = Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; AIC = Akaike information criterion.

p < .05.

^**

p < .01.

^***

p < .001.