. Author manuscript; available in PMC: 2009 Sep 1.

Published in final edited form as: J Behav Ther Exp Psychiatry. 2007 Aug 12;39(3):292–304. doi: 10.1016/j.jbtep.2007.08.002

Table 2.

Anxiety Variables Predicting Perceived Immobility During a 20% CO₂ Challenge

Predicted Variable	Predictors in Set	ΔR²	t for each Predictors	β
Post CO₂ Inhalation API-Freeze
	Step 1	.39
	Condition		−.69	−.03
	Baseline-API-Freeze		14.72^**	.62
	Step 2a
	ASI	.02	4.05^**	.18
	Step 2b
	IES-R	.00	1.53	.07
	Step 2c
	SIAS	.01	3.50^**	.15
	Step 2d
	STAI	.01	3.58^**	.15
	Step 2e
	PSWQ	.01	2.34^*	.10
	Step 2f
	PDSS	.00	1.28	.06

Note. p<.05,

^**

p<.01; API-Freeze = the degree to which you felt that you could not move; ASI = Anxiety Sensitivity Inventory; IES-R= Impact of Events Scale-Revised; SIAS= Social Interaction Anxiety Scale; STAI = Spielberger Trait Anxiety; PSWQ= Penn State Worry Questionnaire; PDSS = Panic Disorder Severity Scale (Panic Attack Frequency).