. Author manuscript; available in PMC: 2010 Aug 2.

Published in final edited form as: Exp Clin Psychopharmacol. 2009 Oct;17(5):356–364. doi: 10.1037/a0016883

Table 2.

Hierarchical Regression Analysis: Interaction of Panic Attack Status and Anxiety Sensitivity Predicting Quit-Day Nicotine Withdrawal Symptoms

Step/variable	Δ R²	t(100)	β	sr²	p
Step 1	.01				ns
Cigs/day		1.02	.10	.01	ns
Step 2	.29				<.001
ASI		5.46	.49	.21	<.001
PA		1.12	.10	.01	ns
Step 3	.04				<.05
AS × PA		−2.36	−.29	.04	<.05

Note. Cigs/day = smoking rate from Smoking History Questionnaire; ASI = Anxiety Sensitivity Index total; PA = panic attack status during hyperventilation challenge (yes/no).