Associations of COVID-19-related fear with kidney disease quality of life and its subscales among hemodialysis patients as modified by health literacy: a multi-hospital survey

Figures & data

Table 1. Patients’ characteristics, kidney disease quality of life, and subscales (N = 972).

Variables	Total n (%)	MCS (Mean ± SD)	PCS (Mean ± SD)	KDCS (Mean ± SD)	KDQOL (Mean ± SD)
Age
18–59	585 (60.2)	41.0 ± 9.8	34.8 ± 9.2	57.3 ± 14.9	50.8 ± 11.3
60–85	387 (39.8)	40.8 ± 10.3	32.4 ± 8.5	53.8 ± 16.4	48.1 ± 12.5
Gender
Male	517 (53.5)	41.1 ± 9.9	34.2 ± 9.2	57.1 ± 15.8	48.7 ± 11.7
Female	450 (46.5)	40.6 ± 10.1	33.4 ± 8.9	54.5 ± 15.3	50.6 ± 11.9
Education
Illiterate or elementary	399 (44.0)	40.7 ± 10.3	32.8 ± 8.9	56.4 ± 15.9	49.8 ± 12.3
Junior high school	281 (31.0)	41.5 ± 8.3	34.6 ± 8.2	54.9 ± 15.3	49.3 ± 11.3
Senior high school or above	226 (25.0)	41.6 ± 10.6	34.2 ± 9.4	55.1 ± 16.5	49.4 ± 12.5
Working status
Not working	334 (34.4)	41.3 ± 7.9	33.4 ± 7.7	55.5 ± 16.8	49.4 ± 12.6
Working	638 (65.6)	40.7 ± 10.9	34.1 ± 9.6	56.2 ± 14.9	44.9 ± 11.5
Married status
Never married	86 (8.8)	41.9 ± 9.8	36.5 ± 9.7	56.8 ± 16.2	50.9 ± 12.50
Ever married	886 (91.2)	40.8 ± 9.9	33.6 ± 8.9	55.8 ± 15.6	49.6 ± 11.8
Social status
Low	274 (28.2)	38.3 ± 10.6	31.9 ± 9.5	49.7 ± 15.0	44.8 ± 11.5
Middle & high	698 (71.8)	42.0 ± 9.5	34.6 ± 8.7	58.4 ± 15.1	51.7 ± 11.50
Medication payment ability
Very or fairly difficult	726 (75.9)	39.3 ± 9.4	33.2 ± 9.0	52.6 ± 14.4	47.2 ± 10.9
Very or fairly easy	231 (24.1)	46.0 ± 9.9	36.0 ± 8.6	66.0 ± 14.8	57.7 ± 11.4
S-COVID-19-S
Without S-COVID-19-S	274 (28.2)	43.3 ± 11.1	35.7 ± 10.7	63.1 ± 15.1	55.2 ± 12.0
With S-COVID-19-S	698 (71.8)	39.8 ± 9.2	32.9 ± 7.9	52.5 ± 14.6	47.1 ± 10.9
BMI, kg/m^2
BMI < 24	876 (90.1)	40.8 ± 9.8	33.8 ± 9.1	56.7 ± 15.5	49.6 ± 11.8
BMI ≥ 24	96 (9.9)	41.9 ± 11.2	33.9 ± 8.1	58.1 ± 16.8	51.3 ± 12.9
Edema
No	527 (54.2)	42.6 ± 10.7	33.5 ± 9.0	57.5 ± 16.2	51.0 ± 12.6
Yes	445 (45.8)	39.0 ± 8.6	34.2 ± 9.0	54.1 ± 14.6	48.2 ± 10.8
Hypothyroidism
No	961 (98.9)	40.9 ± 10.0	33.8 ± 9.0	56.0 ± 15.5	49.8 ± 11.8
Yes	11 (1.1)	42.2 ± 9.1	32.6 ± 10.8	48.2 ± 19.7	44.6 ± 14.0
Hyperthyroidism
No	930 (95.8)	40.9 ± 10.1	34.0 ± 9.1	56.3 ± 15.6	50.0 ± 11.9
Yes	41 (4.2)	42.6 ± 7.7	30.6 ± 7.3	47.5 ± 14.7	43.9 ± 11.2
Hospitalization within one month
No	906 (93.3)	41.2 ± 9.6	34.0 ± 8.7	56.6 ± 14.9	50.3 ± 11.4
Yes	65 (6.7)	37.4 ± 13.7	31.4 ± 13.1	46.3 ± 20.6	42.4 ± 15.9
Physical activity, MET-min/wk
Tertile 1 (MET ≤ 178)	232 (31.8)	38.0 ± 8.9	31.8 ± 8.2	52.9 ± 14.0	46.9 ± 10.2
Tertile 2 (178 < MET ≤ 912)	249 (34.2)	41.2 ± 10.8	33.2 ± 9.1	58.4 ± 14.6	51.3 ± 11.4
Tertile 3 (MET > 912)	248 (34.0)	44.5 ± 12.0	35.5 ± 9.9	62.4 ± 17.0	54.9 ± 13.1
HD vintage, years
HD vintage ≤ 5	550 (56.7)	41.5 ± 9.8	34.4 ± 8.9	56.1 ± 15.8	50.1 ± 12.0
5 < HD vintage ≤ 10	276 (28.5)	40.5 ± 11.1	33.2 ± 9.7	57.5 ± 14.8	50.6 ± 11.6
HD vintage ≥ 10	144 (14.8)	39.6 ± 8.1	33.1 ± 8.0	52.0 ± 15.8	46.8 ± 11.6
CCI (Mean ± SD)	2.1 ± 3.0
Fear of COVID-19 (Mean ± SD)	20.6 ± 6.0
HL index (Mean ± SD)	25.0 ± 9.2
DDL index (Mean ± SD)	24.1 ± 11.6
HDK (Mean ± SD)	5.4 ± 2.5

Abbreviation: KDQOL: kidney disease quality of life; MCS: mental component summary; PCS: physical component summary; KDCS: kidney disease component summary; S-COVID-19-S: suspected COVID-19 symptoms; BMI: body mass index; HD: hemodialysis; CCI: Charlson Comorbidity index; DDL: digital health diet literacy; HDK: hemodialysis dietary knowledge.

Table 2. Associated factors of kidney disease quality of life via bivariate and multivariate linear regression analysis.

Variables	KDQOL
	Bivariate		Multivariate
	B (95% CI)	p	B (95% CI)	p
Age
18–59
60–85	− 2.72 (− 4.24, − 1.20)	0.001*	− 1.26 (− 2.60, 0.09)	0.067
Gender
Male
Female	− 1.88 (−3.38, − 0.38)	0.014*	− 0.37 (− 170, 0.95)	0.581
Education
Illiterate/elementary
Junior high school	− 0.55 (− 2.39, 1.29)	0.558
Senior high school or above	− 0.46 (− 2.43, 1.51)	0.646
Working status
Not working
Working	0.48 (− 1.10, 2.05)	0.553
Married status
Never married
Ever married	− 1.25 (− 3.90, 1.40)	0.354
Social status
Low
Middle & high	6.82 (5.22, 8.43)	0.001*	2.70 (1.13, 4.28)	0.001*
Medication payment ability
Very or fairly difficult
Very or fairly easy	10.52 (8.89, 12.15)	0.001*
S-COVID-19-S
Without S-COVID-19-S
With S-COVID-19-S	− 8.08 (− 9.60, − 6.56)	0.001*	− 6.12 (− 7.66, − 4.58)	0.001*
BMI, kg/m^2
BMI < 24
BMI ≥ 24	1.77 (− 0.74, 4.29)	0.167	1.78 (− 0.34, 3.89)	0.100
Edema
No
Yes	− 2.78 (− 4.27, − 1.29)	0.001*	1.44 (0.01, 2.88)	0.049*
Hypothyroidism
No
Yes	− 5.20 (− 12.26, 1.87)	0.149	1.91 (− 3.99, 7.82)	0.525
Hyperthyroidism
No
Yes	− 6.10 (− 9.80, − 2.39)	0.001*	− 6.84 (− 10.58, − 3.10)	0.001*
Hospitalization within one month
No
Yes	− 7.92 (− 10.87, − 4.96)	0.001*	− 6.74 (− 9.79, − 3.68)	0.001*
Physical activity, MET-min/wk
Tertile 1 (MET ≤ 178)
Tertile 2 (178 < MET ≤ 912)	4.41 (2.33, 6.50)	0.001*
Tertile 3 (MET > 912)	8.03 (5.94, 10.12)	0.001*	1.33 (0.43, 2.22)	0.004*
HD vintage, years
HD vintage ≤ 5
5 < HD vintage ≤ 10	0.51 (− 1.20, 2.23)	0.556
HD vintage ≥ 10	− 3.30 (− 5.47, − 1.12)	0.003*	− 0.24 (− 1.24, 0.77)	0.644
CCI	− 0.57 (− 0.82, − 0.32)	0.001*
Fear of COVID-19	− 1.11 (− 1.22, − 1.01)	0.001*	− 0.91 (− 1.03, − 0.80)	0.001*
HL index	0.32 (0.24, 0.40)	0.001*	0.13 (0.06, 0.21)	0.001*
DDL index	0.16 (0.09, 0.22)	0.001*
HDK	0.72 (0.42, 1.02)	0.001*	0.58 (0.31, 0.85)	0.001*

Abbreviation: KDQOL: kidney disease quality of life; S-COVID-19-S: suspected COVID-19 symptoms; BMI: body mass index; MET: metabolic equivalent task; HD: hemodialysis; CCI: Charlson Comorbidity index; HL: health literacy; DDL: digital health diet literacy; HDK: hemodialysis dietary knowledge; B: unstandardized regression coefficient; CI: confidence interval. * The statistically significant results with a p-value < 0.05.

Table 3. Associated factors of subscales of kidney disease quality of life via bivariate and multivariate linear regression analysis.

Variables	MCS				PCS				KDCS
	Bivariate		Multivariate		Bivariate		Multivariate		Bivariate		Multivariate
	B (95% CI)	p	B (95% CI)	p	B (95% CI)	p	B (95% CI)	p	B (95% CI)	p	B (95% CI)	p
Age
18–59
60–85	− 0.27 (−1.55, 1.02)	0.684			− 2.32 (− 3.47, −1.17)	0.001*	−1.48 (− 2.84, −1.13)	0.031*	− 3.44 (−5.44, − 1.45)	0.001*	− 2.03 (− 3.81, − 0.24)	0.026*
Gender
Male
Female	− 0.53 (−1.80, 0.73)	0.407			− 0.83 (− 1.98, 0.31)	0.153	− 0.83 (− 2.14, 0.47)	0.211	− 2.49 (− 4.46, − 0.52)	0.013*	− 0.33 (−2.09, 1.43)	0.715
Education
Illiterate/elementary
Junior high school	0.87 (− 0.62, 2.37)	0.253			1.82 (0.47, 3.17)	0.008*			− 1.48 (− 3.91, 0.94)	0.230
Senior high school or above	0.98 (0.62, 2.57)	0.231			1.45 (0.01, 2.90)	0.048*	− 0.84 (−1.66, − 0.01)	0.047*	− 1.30 (− 3.89, 1.29)	0.325
Working status
Not working
Working	− 0.64 (−1.97, 0.68)	0.339			0.70 (− 0.49, 1.90)	0.249			0.71 (− 1.26, 2.78)	0.503
Married status
Never married
Ever married	−1.09 (− 3.30, 1.13)	0.335			− 2.94 (− 4.94, − 0.95)	0.004*	− 0.98 (− 3.28, 1.32)	0.403	− 0.91 (− 4.39, 2.56)	0.606
Social status
Low
Middle & high	3.62 (2.24, 5.00)	0.001*	1.06 (− 0.66, 2.77)	0.226	2.69 (1.44, 3.95)	0.001*	0.96 (− 0.67, 2.60)	0.247	8.66 (6.55, 10.78)	0.001*	3.46 (1.37, 5.55)	0.001*
Medication payment ability
Very or fairly difficult
Very or fairly easy	6.67 (5.26, 8.07)	0.001*			2.73 (1.41, 4.05)	0.001*			13.42 (11.36, 15.57)	0.001*
S-COVID-19-S
Without S-COVID-19-S
With S-COVID-19-S	− 3.53 (−4.86, −2.20)	0.001*	− 2.36 (− 4.01, − 0.71)	0.005*	− 2.74 (− 3.95, − 1.53)	0.001*	− 0.77 (− 2.23, 0.68)	0.298	− 10.55 (− 12.54, − 8.55)	0.001*	− 8.21 (−10.25, − 6.17)	0.001*
BMI, kg/m^2
BMI < 24
BMI ≥ 24	1.14 (−0.96, 3.25)	0.287			0.09 (−1.82, 1.99)	0.925			2.40 (− 0.91, 5.70)	0.155	2.14 (− 0.67, 4.95)	0.135
Edema
No
Yes	−3.63 (− 4.87, −2.39)	0.001*			0.68 (− 0.47, 1.82)	0.245			− 3.44 (− 5.40, −1.48)	0.001*	2.46 (0.56, 4.37)	0.011*
Hypothyroidism
No
Yes	1.24 (− 470, 7.18)	0.682			−1.20 (− 6.58, 4.17)	0.661			− 7.81 (− 18.08, 1.47)	0.099	1.06 (− 6.77, 8.90)	0.790
Hyperthyroidism
No
Yes	1.78 (−1.35, 4.91)	0.264			− 3.39 (− 6.21, − 0.57)	0.019*	− 5.07 (−8.57, − 1.60)	0.005*	− 8.75 (− 13.61, − 3.89)	0.001*	− 9.94 (− 14.91, − 4.98)	0.001*
Hospitalization within one month
No
Yes	−3.78 (−6.28, −1.27)	0.003*	− 5.63 (− 9.04, −2.22)	0.001*	− 2.62 (− 4.89, − 0.35)	0.024*	− 4.77 (− 7.98, − 1.55)	0.004*	− 10.28 (− 14.16, − 6.40)	0.001*	− 6.93 (− 10.98, − 2.87)	0.001*
Physical activity, MET-min/wk
Tertile 1 (MET ≤ 178)
Tertile 2 (178 < MET ≤ 912)	3.13 (1.22, 5.05)	0.001*			1.42 (− 0.21, 3.05)	0.087			5.48 (2.74, 8.22)	0.001*
Tertile 3 (MET > 912)	6.50 (4.59, 8.42)	0.001*	1.19 (0.18, 2.19)	0.021*	3.70 (2.07, 5.33)	0.001*	1.44 (0.56, 2.32)	0.001*	9.51 (6.77, 12.26)	0.001*	1.41 (0.23, 2.60)	0.020*
HD vintage, years
HD vintage ≤ 5
5 < HD vintage ≤ 10	−1.08 (−2.52, 0.37)	0.143			− 1.20 (− 2.50, 0.11)	0.072			1.36 (− 0.89, 3.61)	0.237
HD vintage ≥ 10	−1.96 (−3.79, −0.12)	0.036*	−1.33 (− 2.40, − 0.26)	0.015*	− 1.25 (− 2.90, 0.41)	0.141	− 0.92 (− 1.90, 0.06)	0.066	− 4.15 (−7.00, − 1.29)	0.004*	0.33 (− 1.00, 1.66)	0.626
CCI	− 0.69 (− 0.90, − 0.49)	0.001*	− 0.43 (−0.67, − 0.19)	0.001*	− 0.22 (− 0.41, − 0.03)	0.021*	0.025 (−0.24, 0.29)	0.856	− 0.63 (− 0.95, − 0.30)	0.001*
Fear of COVID-19	− 0.54 (− 0.64, − 0.44)	0.001*	− 0.51 (− 0.64, − 0.38)	0.001*	− 0.33 (− 0.42, − 0.23)	0.001*	− 0.22 (− 0.33, − 0.10)	0.001*	− 1.45 (− 1.59, − 1.31)	0.001*	− 1.19 (− 1.34, − 1.03)	0 .001*
HL index	0.12 (0.05, 0.19)	0.001*	0.06 (− 0.02, 0.14)	0.122	0.18 (0.12, 0.24)	0.001*	0.13 (0.05, 0.20)	0.001*	0.40 (0.30, 0.51)	0.001*	0.15 (0.05, 0.25)	0.003*
DDL index	0.07 (0.01, 0.12)	0.017*			0.09 (0.04, 0.14)	0.001*			0.19 (0.11, 0.28)	0.001*
HDK	0.15 (− 0.10, 0.40)	0.242			0.09 (− 0.14, 0.31)	0.461			1.02 (0.63, 1.40)	0.001*	0.80 (0.44, 1.16)	0 .001*

Abbreviation: MCS: mental component summary; PCS: physical component summary; KDCS: kidney disease component summary; S-COVID-19-S: suspected COVID-19 symptoms; BMI: body mass index; MET: metabolic equivalent task; HD: hemodialysis; CCI: Charlson Comorbidity index; HL: health literacy; DDL: digital health diet literacy; HDK: hemodialysis dietary knowledge; B: unstandardized regression coefficient; CI: confidence interval.

* The statistically significant results with a p-value < 0.05.

Table 4. Interaction of health literacy with fear of COVID-19 on KDQOL and KDCS.

	KDQOL*		KDCS *
	B (95% CI)	p	B (95% CI)	p
Fear of COVID-19 (lowest score) x HL (lowest score)	ref		ref
Fear of COVID-19 (one score increment) x HL (lowest score)	− 1.182 (− 1.466, −0.898)	0.001	− 1.550 (− 1.927, − 1.174)	0.001
Fear of COVID-19 (lowest score) x HL (one score increment)	− 0.081 (− 0.302, 0.139)	0.469	− 0.140 (− 0.433, 0.152)	0.347
Fear of COVID-19 (one score increment) x HL (one score increment)	0.011 (0.000, 0.021)	0.042	0.015 (0.001, 0.028)	0.038

Abbreviation: KDQOL: kidney disease quality of life, KDCS: kidney disease component summary; HL: health literacy; CI: confidence interval. * These models were adjusted for age, gender, social, S-COVID-19 S, hyperthyroidism, Physical activity, HD vintage, edema, HDK, hospitalization, BMI, and hypothyroidism.

Figure 1. Simple slope plot of interaction between health literacy and fear of COVID-19 on overall kidney disease quality of life. SD, standard deviation; HL, health literacy.

Figure 2. Simple slope plot of interaction between health literacy and fear of COVID-19 on kidney disease component summary. SD, standard deviation; HL, health literacy.