Relationship Between Severity of Gastrointestinal Symptoms and Anxiety Symptoms in Patients with Chronic Gastrointestinal Disease: The Mediating Role of Illness Perception

Figures & data

Table 1 Demographic and Clinical Characteristics of the Study Population

Characteristics	N=295	BIPQ Score
Age (years)	46.7±12.9	–
Gender
Men	186 (63.1)	36.70±10.92
Women	109 (36.9)	39.73±12.19
Educational level
Primary education	15 (5.1)	44.53±9.32
Secondary education	147 (49.8)	38.21±11.85
Higher education	133 (45.1)	36.63±11.06
Permanent residence
Urban	195 (66.1)	37.23±10.95
Rural	100 (33.9)	38.97±12.43
Job category
Mental work	178 (60.3)	36.75±10.92
Physical work	117 (39.7)	39.45±12.14
Monthly income (yuan)
<3000	64 (21.7)	40.03±11.17
3000–5999	120 (40.7)	38.62±11.78
6000–9999	73 (24.7)	37.29±11.30
>10,000	38 (12.9)	32.61±10.02
Marital status
Married	269 (91.2)	37.36±11.48
Unmarried	26 (8.8)	42.54±10.55
Hypertension
Yes	57 (19.3)	34.05±12.59
No	238 (80.7)	38.72±11.03
Sleep duration
<6	69 (23.4)	40.41±12.94
≥6	226 (76.6)	37.03±10.90

Notes: Results are presented as mean ± SD for continuous variables; frequency (N) and percent (%) for Categorical variables.

Table 2 Relationship Between Severity of GI Symptoms (Measured by GSRS Score) and Anxiety Symptoms

	Model 1		Model 2		Model 3
	β/OR (95% CI)	P value	β/OR (95% CI)	P value	β/OR (95% CI)	P value
Total GSRS score	0.247 (0.012–0.031)	<0.001	0.246 (0.012–0.031)	<0.001	0.214 (0.009–0.028)	<0.001
GSRS score categories
0–4	Reference		Reference		Reference
5–7	2.556 (1.189–5.492)	0.016	2.528 (1.173–5.447)	0.018	2.597 (1.152–5.851)	0.021
8–10	2.994 (1.474–6.083)	0.002	2.959 (1.454–6.024)	0.003	3.182 (1.494–6.779)	0.003
11–37	3.808(1.839–7.889)	<0.001	3.798 (1.828–7.892)	<0.001	3.348 (1.548–7.243)	0.002
P for trend	0.001		0.003		<0.001

Notes: Model 1: no covariates were adjusted; Model 2: age and gender were adjusted; Model 3: all the covariates presented in Table 1 were adjusted.

Table 3 Means, Standard Deviations and Pearson Correlation Coefficients of the Three Variables

Variables	Means	SD	Correlation Matrix
			Severity of GI Symptoms	Illness Perception	Anxiety Symptoms
Severity of GI symptoms	7.83	5.08	–
Illness perception	37.82	11.48	0.321**	–
Anxiety symptoms	3.01	3.54	0.308**	0.317**	–

Note: **Correlation is significant at the 0.01 level (2-tailed).

Table 4 Results of Mediation Analysis for the Mediating Effect of Illness Perception

Paths/Effect	Standardized Coefficient	SE	T	P	95% CI
Severity of GI symptoms--Anxiety symptoms	0.230	0.040	4.028	<0.001	0.082–0.239
Severity of GI symptoms--Illness perception	0.321	0.125	5.806	<0.001	0.480–0.972
Illness perception--Anxiety symptoms	0.243	0.018	4.259	<0.001	0.040–0.110
Direct effect	0.230	0.040	4.028	<0.001	0.082–0.239
Indirect effect	0.078	0.015			0.029–0.087
Total effect	0.308	0.039	5.538	<0.001	0.138–0.291

Figure 1 A model for the mediating effect of Illness perception.

Notes: c path represents total effect; a*b path represents indirect effect; c’ path represents direct effect. All path standardized coefficients and P values are displayed in the model.