. Author manuscript; available in PMC: 2016 Apr 1.

Published in final edited form as: J Health Psychol. 2013 Oct 22;20(4):369–379. doi: 10.1177/1359105313502564

Table 2.

Hierarchical regressions of individual and incremental contributions of somatization and trait anxiety.

	Variable	R²	R² change	F	β	t	% Unique variance
Regressions assessing individual contributions of variables
Maximum pain report (0–100 mm VAS)
	Trait anxiety regression	0.13		3.82^*
Step 1	Sex				0.16	1.44
Step 2	GI inflammation				0.13	1.19
Step 3	Trait anxiety		0.09		0.30	2.75^*	8.64
	Somatization regression	0.17		5.25^*
Step 1	Sex				0.17	1.64
Step 2	GI inflammation				0.04	0.38
Step 3	Somatization		0.13		0.37	3.41^*	12.67
Number of pain episodes
	Trait anxiety regression	0.11		3.09^*
Step 1	Sex				0.17	1.53
Step 2	GI inflammation				0.03	0.31
Step 3	Trait anxiety		0.07		0.27	2.50^*	7.29
	Somatization regression	0.20		6.16^*
Step 1	Sex				0.18	1.75
Step 2	GI inflammation				−0.06	−0.59
Step 3	Somatization		0.16		0.41	3.89^*	16.00
Regressions assessing incremental value of trait anxiety
Maximum pain report (0–100 mm VAS)		0.20		4.56^*
Step 1	Sex				0.17	1.66
	GI inflammation				0.06	0.56
Step 2	Somatization		0.21		0.29	2.43^*	6.30
Step 3	Trait anxiety		0.01		0.17	1.50	2.40
Number of pain episodes		0.21		4.86^*
Step 1	Sex				0.18	1.76
	GI inflammation				−0.05	−0.47
Step 2	Somatization		0.21		0.36	3.05^*	9.86
Step 3	Trait anxiety		0.00		0.11	0.99	1.04

VAS: visual analog scale; GI: gastrointestinal.

R² change is provided for trait anxiety and somatization.

p < .05.