Effect of Disease Severity on the Quality of Life and Sense of Stigmatization in Psoriatics

Figures & data

Table 1 Statistical Characteristics of Psoriasis Severity, Quality of Life and Stigmatization Levels Determined with the 6- and 33-Item Scale

Psychometric Measures	Mean	Median	Std. dev.	Q1	Q3	Min	Max
PASI
Severity of psoriasis	14.0	11.3	10.1	6.7	18.8	1.7	49.2
DLQI
Quality of life	10.8	10	7.3	5	16	0	28
33-item questionnaire (stigmatization)
Overall score	81.6	80	24.3	61	99	33	132
Anticipation of rejection	22.9	23	7.6	17	29	7	40
Feeling of being flawed	13.3	11	6.5	8	19	2	26
Sensitivity to the opinions of others	12.1	12	5.5	8	17	1	28
Guilt and shame	14.0	14	4.1	11	17	6	23
Positive attitudes	8.8	9	3.8	7	11	1	17
Secretiveness	10.5	10	4.4	7	14	3	20
6-item questionnaire
Stigmatization	7.5	8	4.7	3	11	0	18

Abbreviations: Std. dev., standard deviation; Q_{1 and} Q₃, lower and upper quartile, respectively; min., minimum value; max., maximum value.

Figure 1 Distributions of the quality of life (C) scores and stigmatization levels determined with the 6- (B) and 33-item scale (A).

Table 2 Relationships of Psoriasis Severity with the Quality of Life and Stigmatization Levels (Spearman Correlation Coefficient)

Quality of Life, Stigmatization		Severity of Psoriasis (PASI)
DLQI		0.62 (p = 0.0000)
33-item scale	Overall score	0.46 (p = 0.0000)
	Anticipation of rejection	0.48 (p = 0.0000)
	Feeling of being flawed	0.38 (p = 0.0000)
	Sensitivity to the opinions of others	0.36 (p = 0.0001)
	Guilt and shame	0.07 (p = 0.4584)
	Positive attitudes	0.41 (p = 0.0000)
	Secretiveness	0.29 (p = 0.0024)
6-item scale		0.48 (p = 0.0000)

Notes: p – assessment of significance.

Figure 2 Distributions of DLQI scores (A) and overall scores for the 33-item scale (B) according to PASI.

Table 3 Univariate Analysis. Relationships of Psoriasis Severity, Stigmatization and Quality of Life with Sociodemographic Variables

Variables		Severity of Psoriasis, Stigmatization, Quality of Life
		PASI	DLQI	33-Item Scale							6-Item Scale
				Overall Score	Anticipation of Rejection	Feeling of Being Flawed	Sensitivity to the Opinions of Others	Guilt and Shame	Positive Attitudes	Secretiveness
Gender	Women (N = 52)	16.6±12.1	11.8±8.0	85.8±26.2	24.0±8.3	14.2±6.9	12.4±5.6	14.3±4.0	9.3±3.8	11.6±4.6	8.3±4.9
	Men (N = 59)	11.6±7.3	10.0±6.6	77.9±22.0	21.9±6.8	12.5±6.0	11.9±5.5	13.7±4.2	8.4±3.9	9.5±4.1	6.7±4.5
	p^a	0.0082	0.2045	0.0887	0.1426	0.1516	0.6578	0.4307	0.2582	0.0143	0.0900
Age [years]	18–30 (N = 16)	12.3±12.1	9.6±8.1	77.9±26.9	23.2±8.5	11.9±7.2	11.4±5.9	13.4±3.7	7.6±4.2	10.4±4.3	5.4±5.3
	31–40 (N = 22)	15.5±10.8	11.4±8.7	83.1±29.1	23.3±6.5	14.8±6.9	12.5±5.9	13.5±5.4	8.3±4.6	10.8±4.9	8.3±5.6
	41–50 (N = 21)	15.6±12.0	12.5±6.7	90.0±24.6	25.3±8.8	14.3±6.4	14.1±4.6	15.8±4.2	10.3±4.2	10.2±3.8	8.2±4.4
	51–60 (N = 31)	13.8±9.2	10.4±6.5	78.1±23.5	22.7±7.6	13.0±6.8	11.1±5.6	13.0±3.9	8.1±3.4	10.1±4.7	7.0±4.5
	>60 (N = 21)	12.1±6.9	10.0±7.1	79.7±16.1	20.0±6.2	12.2±5.1	11.8±5.6	14.7±2.0	9.9±2.4	11.1±4.6	8.0±3.6
	p^b	0.7017	0.7230	0.4446	0.2633	0.5411	0.3859	0.1383	0.1079	0.9337	0.2975
Education	Vocational (N = 22)	12.3±8.9	11.0±6.0	75.7±14.5	20.5±6.2	10.7±4.0	12.2±4.9	14.1±3.6	8.7±3.2	9.4±4.1	6.8±3.0
	Secondary (N = 52)	12.4±8.0	9.0±6.9	79.9±23.5	22.1±6.8	12.8±6.2	11.3±5.5	14.0±3.8	9.2±3.9	10.4±4.2	6.8±4.9
	Higher (N = 37)	17.2±12.6	13.3±7.9	87.5±28.8	25.3±8.8	15.4±7.4	13.2±5.8	13.9±4.8	8.4±4.1	11.4±4.9	8.7±5.2
	p^b	0.0603	0.0212	0.1542	0.0413	0.0197	0.3033	0.9810	0.5598	0.2565	0.1343
Duration of psoriasis [years]	rS^c	−0.02	−0.03	0.01	−0.03	−0.02	0.00	−0.03	0.10	0.03	0.00
	p	0.8644	0.7936	0.9003	0.7544	0.8654	0.9829	0.7640	0.3166	0.7555	0.9639

Notes: ^aStudent’s t-test for independent variables; ^bANOVA test; ^cSpearman correlation coefficient (r_S) and its significance (p).

Table 4 Effect of Selected Demographic Factors on Stigmatization Levels and Quality of Life After the Adjustment for Disease Severity (PASI Scores) – The Results of Covariance Analysis

Demographic Features	Mean Difference Between Groups	Severity of Stigmatization and Quality of Life
		DLQI	33-Item Scale							6-Item Scale
			Overall Score	Anticipation of Rejection	Feeling of Being Flawed	Sensitivity to the Opinions of Others	Guilt and Shame	Positive Attitudes	Secretiveness
Gender	Men vs women	0.4	−2.0	−0.2	−0.4	0.5	−0.3	−0.1	−1.5	−0.4
	p	0.7337	0.6384	0.8795	0.7326	0.6157	0.6710	0.9116	0.0779	0.5877
Age [years]	31–50 years vs others	0.8	4.9	1.3	1.4	1.4	0.8	0.3	−0.3	0.7
	p	0.5137	0.2385	0.3129	0.2379	0.1751	0.2899	0.6194	0.6811	0.3720
Education	Higher vs non-higher	1.8	3.3	1.9	2.0	0.7	−0.4	−1.5	0.7	0.9
	p	0.1477	0.4558	0.1668	0.1032	0.5154	0.6140	0.0379	0.4552	0.3016

Note: p – assessment of significance of difference between groups from analysis of covariance (with PASI as covariate).

Figure 3 Analysis of regression; relationships of the quality of life (A) and secretiveness (B) scores with PASI, stratified according to patient gender.

Figure 4 Analysis of covariance; relationships of the quality of life (A) and positive attitudes (B) scores with patient education.

Table 5 Analysis of Regression. Relationships Between DLQI (Quality of Life) and Independent Variables – Results for Models with All Independent Variables

Effects	DLQI R^2 = 36.9% F = 7.4 p = 0.0000
	B (95% c.i.)	p	β
Gender (male vs female)	−0.903 (−5.209; 3.403)	0.6783	−0.06
Education (higher vs other)	0.624 (−3.753; 5.000)	0.7780	0.04
Age (31–50 vs others)	0.014 (−4.065; 4.093)	0.9946	0.00
PASI [pts]	0.434 (0.302; 0.565)	0.0000	0.60
Duartion of psiorasis [years]	−0.006 (−0.101; 0.088)	0.8936	−0.01
Gender × PASI	0.122 (−0.162; 0.405)	0.3971	0.14
Education × PASI	0.077 (−0.172; 0.327)	0.5396	0.09
Age × PASI	0.053 (−0.184; 0.290)	0.6588	0.06

Notes: R² – coefficient of determination (the percentage of the response variable variation that is explained by a model); Test statistic F and p-value for assessment of significance of whole model. B – regression coefficient (with 95% confidence interval). p – assessment of significance; ß – standardize regression coefficient.