Mediating role of social support in dysphoria, despondency, and quality of life in patients undergoing maintenance hemodialysis

Table 1 Demographic information of patients undergoing Maintenance Hemodialysis

Variables	Categories	Number, n (%)
Sex	Male	158 (54.67)
	Female	131 (45.33)
Age	< 45 yr	39 (13.50)
	45-60 yr	128 (44.29)
	> 60 yr	122 (42.21)
Education	Below high school	164 (56.75)
	High school and above	125 (43.25)
Marital status	Married	242 (83.74)
	Single (unmarried, divorced, widowed)	47 (16.26)
Monthly income	< 3000 yuan	55 (19.03)
	3000-5000 yuan	129 (44.64)
	> 5000 yuan	105 (36.33)
Medical insurance status	Medical insurance/social insurance	212 (73.36)
	Self-payment	77 (26.64)

Table 2 Various scores of social support in patients undergoing Maintenance Hemodialysis

Items	Number, n (%)	Score range (points)	Score (points)
Subjective support	289 (100.00)	8-32	19 (12, 26)
Objective support	289 (100.00)	1-22	9 (5, 16)
The utilization of social support	289 (100.00)	3-12	7 (5, 10)
Total score	289 (100.00)	13-60	39 (24.5, 46)
Low level of support	63 (20.80)	14-22	20 (18, 21)
High levels of support	128 (44.29)	23-44	37 (30, 41)
High levels of support	98 (33.91)	45-60	49 (46, 53)

Table 3 Dysphoria scores and levels in patients undergoing Maintenance Hemodialysis

	Number, n (%)	Score (points)
Standard score	289 (100.00)	52 (42, 65)
No dysphoria	115 (39.79)	41 (35, 43)
Mild dysphoria	73 (25.26)	53 (51, 56)
Moderate dysphoria	54 (18.69)	65 (62, 66)
Severe dysphoria	47 (16.26)	77 (74, 86)

Table 4 Despondency scores and levels in patients undergoing Maintenance Hemodialysis

	Number, n (%)	Score (points)
Standard score	289 (100.00)	55 (45, 67)
No despondency	132 (45.67)	43 (37, 48)
Mild despondency	63 (21.80)	57 (56, 61)
Moderate despondency	44 (15.23)	67 (64, 70.5)
Severe despondency	50 (17.30)	81 (77, 87)

Table 5 Quality of life scores of patients undergoing Maintenance Hemodialysis

	Score (points)
PF	55 (25, 80)
RP	50 (25, 75)
BP	62.5 (46, 87.5)
GH	62 (40, 82)
VT	60 (40, 80)
SF	64 (44, 84)
RE	66.67 (44.44, 88.89)
MH	66.67 (0, 100)
Quality of life (PCS)	105.11 (80.70, 126.64)
Quality of life (MCS)	111.64 (84.74, 130.18)

PF: Physical functioning; RP: Role physical; BP: Bodily pain; GH: General health; VT: Vitality; SF: Social functioning; RE: Role emotional; MH: Mental health; PCS: Physical component summary; MCS: Mental component summary.

Table 6 Analysis of differences in quality-of-life scores of patients undergoing Maintenance Hemodialysis with different levels of social support

	Low level of support	Medium level of support	High level of support	H	P value
Physical functioning	10 (5, 20)	50 (30, 70)	85 (73.75, 91.25)	169.696	< 0.001
Role physical	0 (0, 25)	50 (25, 75)	75 (75, 100)	135.561	< 0.001
Bodily pain	49.5 (33.5, 58.5)	58.5 (37.5, 69.5)	94 (81.5, 100)	109.892	< 0.001
General health	25 (20, 35)	57 (45, 67)	87 (75, 92)	180.510	< 0.001
Vitality	30 (20, 40)	57.5 (46.25, 70)	85 (73.75, 91.25)	164.913	< 0.001
Mental health	32 (20, 40)	64 (52, 76)	92 (76, 96)	170.850	< 0.001
Social functioning	22.22 (11.11, 22.22)	55.56 (44.44, 75)	88.89 (77.785, 100)	173.945	< 0.001
Role emotional	0 (0, 33.33)	66.67 (0, 100)	66.67 (66.67, 100)	57.644	< 0.001
Quality of life (PCS)	73.17 (60.73, 73.17)	99.04 (83.29, 113.28)	129.76 (121.32, 140.17)	177.620	< 0.001
Quality of life (MCS)	73.72 (64.62, 87.28)	106.86 (88.02, 127.40)	129.16 (116, 138.81)	115.293	< 0.001

PCS: Physical component summary; MCS: Mental component summary.

Table 7 Correlation analysis of social support, dysphoria, despondency, and quality of life in patients undergoing Maintenance Hemodialysis

	Social support	Dysphoria	Despondency	Quality of life (PCS)	Quality of life (MCS)
Social support	1.000
Dysphoria	-0.584b	1.000
Despondency	-0.549b	0.435b	1.000
Quality of life (PCS)	0.718b	-0.502b	-0.540b	1.000
Quality of life (MCS)	0.600b	-0.454b	-0.404b	0.206b	1.000

^bP < 0.01 (two-tailed).

PCS: Physical component summary; MCS: Mental component summary.

Table 8 The effect of dysphoria on quality of life and the mediating effect of social support

Model path	Standard regression equation	β	SE	t	P value
Step 1	Y1 = -0.869A	-0.869	0.087	-9.963	< 0.001
Step 2	M = -0.450A	-0.450	0.038	-11.998	< 0.001
Step 3	Y1 = -0.267A + 1.340M	-0.267	0.088	-3.046	0.003
		1.340	0.113	11.902	< 0.001
Step 1	Y2 = -0.823A	-0.823	0.090	-9.190	< 0.001
Step 2	M = -0.450A	-0.450	0.038	-11.998	< 0.001
Step 3	Y2 = -0.329A + 1.098M	-0.329	0.098	-3.371	< 0.001
		1.098	0.126	8.752	< 0.001

Note: Y₁ = Quality of life (physical component summary), Y₂ = Quality of life (mental component summary), M = Social support, and A = Dysphoria.

Table 9 The effect of despondency on quality of life and the mediating effect of social support

Model path	Standard regression equation	β	SE	t	P value
Step 1	Y1 = -0.896B	-0.896	0.084	-10.709	< 0.001
Step 2	M = -0.412B	-0.412	0.038	-10.891	< 0.001
Step 3	Y1 = -0.372B + 1.274M	-0.372	0.082	-4564	< 0.001
		1.274	0.107	11.888	< 0.001
Step 1	Y2 = -0.717B	-0.717	0.090	-7.945	< 0.001
Step 2	M = -0.412B	-0.412	0.038	-10.891	< 0.001
Step 3	Y2 = -0.232B + 1.178M	-0.232	0.093	-2.483	0.014
		1.178	0.123	9.590	< 0.001

Note: Y₁ = Quality of life (physical component summary); Y₂ = Quality of life (mental component summary); M = Social support; B = Despondency.

Table 10 Results of the mediation effect test

	The path		Coeff	SE	LLCI	ULCI	Relative effect Size (%)
Dysphoria	Direct effect	Dysphoria → Quality of life (PCS)	-0.266	0.088	-0.439	-0.094	30.61
	Indirect effect	Dysphoria → Social support → Quality of life (PCS)	-0.603	0.064	-0.731	-0.482	69.39
	Total effect		-0.869	0.087	-1.041	-0.698
Dysphoria	Direct effect	Dysphoria → Quality of life (MCS)	-0.330	0.098	-0.521	-0.137	40.10
	Indirect effect	Dysphoria → Social support → Quality of life (MCS)	-0.493	0.071	-0.644	-0.366	59.90
	Total effect		-0.823	0.090	-0.999	-0.647
Despondency	Direct effect	Despondency → Quality of life (PCS)	-0.372	0.082	-0.533	-0.212	41.52
	Indirect effect	Despondency → Social support → Quality of life (PCS)	-0.524	0.063	-0.659	-0.412	50.48
	Total effect		-0.896	0.084	-1.061	-0.732
Despondency	Direct effect	Despondency → Quality of life (MCS)	-0.232	0.093	-0.416	-0.048	32.36
	Indirect effect	Despondency → Social support → Quality of life (MCS)	-0.485	0.065	-0.620	-0.367	67.64
	Total effect		-0.717	0.090	-0.894	-0.539

LLCI: Lower limit of 95%CI; ULCI: Upper limit of 95%CI; PCS: Physical component summary; MCS: Mental component summary.