Table 3.

IDQ-S Subscales on Insomnia Severity Index Subscale Scores

	ISI Severity subscale			ISI Impact subscale
Variable	β	t	p	β	t	p
Gender	−.006	−1.018	.310	.037	.603	.547
Age	.024	.379	.705	−.043	−.704	.482
Race	−.005	−.074	.941	.062	1.012	.313
HSIa	.114	1.663	.098	.117	1.810	.072
DIIb	.047	.713	.477	.095	1.511	.132
IDQ-Sc –Lack of Cognitive Coping	−.038	−.580	.563	.050	.798	.426
IDQ-Sc –Withdrawal Intolerance	.283	4.051	<.001	.389	5.879	<.001
R 2		.129			.220
ΔR2		.066			.125
F for ΔR2		16.413**			34.561**

Note: N = 224. Results shown are from the second step of each linear regression model; β = standardized beta weights; Race: Reference group = white; Gender: Reference group = female

^aHeaviness of Smoking Index

^bDistress Intolerance Index

^cIntolerance for Smoking Abstinence Discomfort Questionnaire

^*p < .05

^**p < .01