Using eye movements in the dot-probe paradigm to investigate attention bias in illness anxiety disorder

Table 1 Demographic characteristics and clinical symptoms of the illness anxiety disorder and healthy control groups

Item	Patient group: IAD group, n = 30	Control group: HC group, n = 30	t/χ2	P value
Age in yr	30.03 ± 8.73	30.70 ± 8.61	−0.298	0.767
Sex, male/female	19/11	14/16	1.684	0.194
Educational background
Junior high school	5	5
Senior vocational/high school	4	4
Junior college/university	20	20
Master’s degree or higher education	1	1
IAS	47.53 ± 16.44	27.43 ± 13.07	5.240c	< 0.001
WI	7.60 ± 3.83	3.13 ± 1.98	5.677c	< 0.001
BAI	38.17 ± 12.09	24.57 ± 4.33	5.799c	< 0.001
BDI	18.10 ± 9.65	6.13 ± 6.71	5.577c	< 0.001

^cP < 0.001.

BAI: Beck anxiety inventory; BDI: Beck depression inventory; HC: Healthy control; IAD: Illness anxiety disorder; IAS: Illness attitudes scale; WI: Whiteley index.

Table 2 Attentional bias-related eye-movement data

Item	Image classification	IAD group, n = 30	HC group, n = 30	t	P value
First-fixation direction bias as %
Disease–threat	Disease	49.90 ± 9.93	49.94 ± 8.96	0.341	0.734
	Threat	50.10 ± 9.93	50.94 ± 8.96	-0.341	0.734
Disease–positive	Disease	34.90 ± 12.23	32.92 ± 9.77	0.693	0.491
	Positive	65.10 ± 12.23	67.08 ± 9.77	-0.693	0.491
Disease–neutral	Disease	45.00 ± 7.81	50.21 ± 8.53	-2.467a	0.017
	Neutral	55.00 ± 7.81	49.79 ± 8.53	2.467a	0.017
First-fixation duration bias in ms
Disease–threat	Disease	281.20 ± 61.47	246.40 ± 30.99	2.769b	0.008
	Threat	296.86 ± 58.13	266.37 ± 40.17	2.363a	0.022
Disease–positive	Disease	272.16 ± 61.83	246.20 ± 35.4	1.996	0.051
	Positive	259.41 ± 49.95	238.71 ± 48.83	1.623	0.110
Disease–neutral	Disease	280.48 ± 55.15	252.81 ± 45.07	2.128a	0.038
	Neutral	288.28 ± 59.08	264.67 ± 47.27	1.709	0.093
Overall gaze duration bias in ms
Disease–threat	Disease	44.90 ± 4.13	44.51 ± 3.86	0.388	0.700
	Threat	55.09 ± 4.13	55.49 ± 3.85	-0.388	0.700
Disease–positive	Disease	46.45 ± 5.3	44.35 ± 6.21	1.407	0.165
	Positive	53.55 ± 5.3	55.65 ± 6.21	-1.407	0.165
Disease–neutral	Disease	47.18 ± 4.13	46.97 ± 4.50	0.185	0.854
	Neutral	52.82 ± 4.12	53.03 ± 4.50	-0.185	0.854
Overall fixation frequency bias as %
Disease–threat	Disease	45.63 ± 3.24	45.59 ± 3.83	0.051	0.960
	Threat	54.37 ± 3.24	54.41 ± 3.83	-0.051	0.960
Disease–positive	Disease	46.93 ± 4.43	44.67 ± 5.06	1.841	0.071
	Positive	53.07 ± 4.43	55.33 ± 5.06	-1.841	0.071
Disease–neutral	Disease	48.44 ± 3.78	48.76 ± 3.50	-0.341	0.735
	Neutral	51.56 ± 3.78	51.24 ± 3.50	0.341	0.735

^aP < 0.05.

^bP < 0.01.

HC: Healthy control; IAD: Illness anxiety disorder.

Table 3 Regression analysis of overall gaze duration bias (ms) and beck anxiety inventory

	Adjusted R-square	Regression coefficient (95%CI)	P value
Disease image	0.055	0.156 (0.004 to 0.308)	0.045
Threat image	0.055	-0.156 (-0.308 to -0.004)	0.045

CI: Confidence interval.