Real world insights for psoriasis: the association of severity of skin lesions with work productivity, medical consumption costs and quality of life

Figures & data

Table 1. Characteristics of study population, overall and stratified by self-reported affected body surface area of skin lesions in psoriasis.

Characteristic	Overall (N = 501)	BSA categories
		BSA 0–1% n = 143 (29%)	BSA > 1% n = 358 (71%)
Age (years)	43.1 ± 11.5	47.7 ± 13.9	41.2 ± 9.8
18–35 years	112 (22%)	32 (22%)	80 (22%)
36–67 years	361 (72%)	96 (67%)	265 (74%)
≥68 years	28 (6%)	15 (10%)	13 (4%)
Female (%)	181 (36%)	74 (52%)	107 (30%)
Educational level (%)
Low	50 (10%)	6 (4%)	44 (12%)
Middle	299 (60%)	78 (55%)	221 (62%)
High	152 (30%)	59 (41%)	93 (26%)
Paid employment/schooling	375 (75%)	102 (71%)	273 (76%)
Years since first diagnosis	11.0 (4.0–19.0)	12.0 (3.0–23.0)	11.0 (7.0–17.0)
Concomitant treatment^a
No medication	71 (14%)	46 (32%)	25 (7%)
Phototherapy	66 (13%)	16 (11%)	50 (14%)
Topical	329 (66%)	86 (60%)	243 (68%)
Systemic – classical	235 (47%)	37 (26%)	198 (55%)
Systemic – biologics	222 (44%)	29 (20%)	193 (54%)
Concomitant treatment (highest category in shown order)^b
No medication	71 (14%)	46 (32%)	25 (7%)
Phototherapy	3 (1%)	1 (1%)	2 (1%)
Topical	115 (23%)	50 (35%)	65 (18%)
Systemic – conventional	90 (18%)	17 (12%)	73 (20%)
Systemic – biologics	222 (44%)	29 (20%)	193 (54%)
History of comorbidities^a
Psoriatic arthritis	220 (44%)	35 (24%)	185 (52%)
Cardiovascular disease	107 (21%)	18 (13%)	89 (25%)
Diabetes mellitus	115 (23%)	15 (10%)	100 (28%)
Depression or anxiety	132 (26%)	33 (23%)	99 (28%)
Other auto-immune disorder	6 (1%)	2 (1%)	4 (1%)

Characteristics of the study population. Values are expressed as No. (%) for categorical variables and mean ± standard deviation or median (1st quartile – 3rd quartile) for continuous variables, unless specified otherwise. The sum of percentages for multiple-choice questions exceeds 100%, and percentages may not always add up to 100% due to independent rounding.

BSA: Body surface area; N: sample size.

^a Respondents could choose more than one answer.

^b We also depicted concomitant treatment according to the highest category per respondent (single value per respondent), where we designated the highest category for each respondent in descending order from systemic-biologics, systemic-conventional, topical, phototherapy, none.

Table 2. Patient-reported outcomes on work productivity, medical consumption, and quality of life, overall and stratified by body surface area.

Questionnaire	Outcome variables (unit)	Overall	BSA categories
			BSA 0–1%	BSA > 1%
Work productivity (WPAI)	Overall work impairment due to psoriasis (%)^a	58 (0–87)	6 (0–67)	77 (9–90)
	Ordinal categories
	0%	54 (26%)	28 (37%)	26 (20%)
	1–63%	75 (37%)	32 (42%)	43 (33%)
	63–100%	76 (37%)	16 (21%)	60 (47%)
Medical Consumption (iMCQ)	Medical consumption costs (€)	333 (0–1373)	138 (0–428)	809 (0–2722)
	Ordinal categories
	€ 0	131 (26%)	39 (27%)	92 (26%)
	€ 1–360	124 (25%)	61 (43%)	63 (18%)
	€ 361–1864	123 (25%)	33 (23%)	90 (25%)
	€ >1864	123 (25%)	10 (7%)	113 (32%)
Health-related quality of life (EQ-5D-5L)	Overall utility score	0.85 (0.74–0.82)	0.89 (0.82–1.00)	0.84 (0.71–0.92)
	Ordinal categories
	<0.8	168 (34%)	30 (21%)	138 (39%)
	0.81–0.99	198 (40%)	57 (40%)	141 (39%)
	1.00	132 (27%)	56 (39%)	79 (22%)
Dermatology-related quality of life (DLQI)	DLQI score	14 (3-25)	3 (1-10)	20 (6-26)
	Ordinal categories
	0–5	169 (34%)	86 (60%)	83 (23%)
	>5–23	175 (35%)	40 (28%)	135 (38%)
	>23	157 (31%)	17 (12%)	140 (39%)

Characteristics of the study population. Values are expressed as no. (%) for categorical variables and mean ± standard deviation or median (1^st quartile – 3^rd quartile) for continuous variables, unless specified otherwise. Percentages may not add up to 100% exactly due to rounding.

^a N = 205.

BSA: Body surface area; N: sample size.

Table 3. Associations of severity of skin lesions in psoriasis with overall work impairment, medical consumption cost, and health-related quality of life.

Model	BSA category	cOR (95% confidence interval)
		Overall work impairment due to psoriasis (0%; 1–79%; 80–100%)	Medical consumption cost in € (0; 1–360; 361–1864; >1864)	EQ-5D-5L utility score (<0.8; 0.8–0.99; 1)	Total DLQI score (0–5; 6–23; 24–30)
		N = 205	N = 501	N = 501	N = 501
Model 1	BSA 0–1%	1.00 (ref)	1.00 (ref)	1.00 (ref)	1.00 (ref)
	BSA >1%	2.44 (1.40–4.29)	2.06 (1.45–2.94)	0.42 (0.28–0.61)	3.59 (2.40–5.42)
Model 2	BSA 0–1%	1.00 (ref)	1.00 (ref)	1.00 (ref)	1.00 (ref)
	BSA >1%	1.94 (1.06–3.58)	1.92 (1.30–2.84)	0.49 (0.32–0.73)	2.48 (1.61–3.82)

Odds ratios were obtained with ordinal logistic regression models (providing a common odds ratio over ordinal categories of the outcome).

Estimates were adjusted for age, sex (model 1), and additionally for education, years since diagnosis of psoriasis, and number of comorbidities (model 2).

Since obtaining confidence intervals through the standard error for ordinal regression may biased intervals, we obtained 95% confidence intervals through profiling the likelihood function.

BSA: Body surface area; CI: Confidence interval; cOR: Common odds ratio; DLQI: Dermatological Life Quality Index; EQ-5D: EuroQoL 5-item questionnaire; N: sample size.

Table 4. Associations of psoriasis severity determined by BSA and DLQI with overall work impairment, medical consumption cost, and health-related quality of life.

Severity categories	Number of respondents^a	cOR (95% confidence interval)
		Overall work impairment due to psoriasis (0%; 1–79%; 80–100%)	Overall medical consumption cost in € (0; 1–360; 361–1864; >1864)	EQ-5D-5L overall health utility score (<0.80; 0.80–0.99; 1.00)
		N = 205	N = 501	N = 501
Low (BSA ≤ 5% and DLQI score ≤5)	164	1.00 (ref)	1.00 (ref)	1.00 (ref)
Moderate-high (BSA > 5% or DLQI >5)	337	3.80 (2.01–7.30)	2.93 (2.03–4.25)	1.20 (0.80–1.81)

Odds ratios were obtained with ordinal logistic regression models (providing a common odds ratio over ordinal categories of the outcome). Estimates were adjusted for age, sex, education, years since diagnosis of psoriasis, and number of comorbidities.

Since obtaining confidence intervals through the standard error for ordinal regression may biased intervals, we obtained 95% confidence intervals through profiling the likelihood function.

^a Number of respondents for the analysis with overall work impairment due to psoriasis (n = 205) were 79 for low severity and 126 for moderate-high severity.

BSA: Body surface area; CI: Confidence interval; cOR: Common odds ratio; DLQI: Dermatological Life Quality Index; EQ-5D: EuroQoL 5-item questionnaire; N: sample size.

Table 5. Associations of BSA with other outcomes of work productivity and health-related quality of life.

BSA category	cOR (95% confidence interval)
	Work time absent due to psoriasis in last week (0%; 1–50%; 51–100%)	When present, work productivity impacted by psoriasis (0.0;>0.0–7.1; 7.2–10)	Impact psoriasis on daily functioning (0.0; >0.0–7.1; 7.2–10)	EQ-VAS (0–70; 71–84; 85–100)
	N = 205	N = 487	N = 501	N = 501
BSA 0-1%	1.00 (ref)	1.00 (ref)	1.00 (ref)	1.00 (ref)
BSA >1%	2.40 (1.19–5.01)	2.20 (1.38-3.51)	2.54 (1.60–4.07)	0.36 (0.24–0.54)

Odds ratios were obtained with ordinal logistic regression models (providing a common odds ratio over ordinal categories of the outcome). Estimates were adjusted for age, sex, education, years since diagnosis of psoriasis, and number of comorbidities.

Since obtaining confidence intervals through the standard error for ordinal regression may bias intervals, we obtained 95% confidence intervals through profiling the likelihood function.

Estimates were adjusted for age, sex, education, years since diagnosis of psoriasis, and number of comorbidities present.

BSA: Body surface area; CI: confidence interval; cOR: common odds ratio; EQ-VAS: EuroQoL Visual analogue scale; N: sample size; SD: standard deviation.

Table 6. Setting treatment goals and overall treatment satisfaction in the past year.

Characteristic	Overall (N = 501)	BSA categories
		BSA 0-1% n = 143 (29%)	BSA > 1% n = 358 (71%)
Treatment goals were discussed
Yes	216 (43%)	57 (40%)	159 (44%)
No	202 (40%)	42 (29%)	160 (45%)
Not currently treated	83 (17%)	44 (31%)	39 (11%)
If goals not discussed (n = 202): did you find this problematic?
Yes	20 (9%)	5 (9%)	15 (9%)
No	196 (91%)	52 (91%)	144 (91%)
If goals discussed (n = 216): what were they? (multiple choice)
Absence of symptoms	73 (34%)	20 (35%)	53 (33%)
Decrease in symptoms	122 (56%)	21 (37%)	101 (64%)
Absence of skin lesions	103 (48%)	20 (35%)	83 (52%)
Decrease in skin lesions	92 (43%)	23 (40%)	69 (43%)
Decrease in localized lesions	68 (31%)	10 (18%)	58 (36%)
Other	4 (3%)	4 (7%)	4 (3%)
If goals discussed (n = 216); were they met?
Yes, all	24 (12%)	5 (12%)	19 (12%)
Yes, some	154 (76%)	27 (64%)	127 (79%)
No, none	24 (12%)	10 (23%)	14 (9%)
Overall treatment satisfaction in the past year
Very satisfied	159 (32%)	42 (29%)	117 (33%)
Somewhat satisfied	212 (42%)	38 (27%)	174 (49%)
Not (dis)satisfied	42 (8%)	15 (10%)	27 (8%)
Somewhat dissatisfied	15 (3%)	5 (4%)	10 (3%)
Very dissatisfied	10 (2%)	4 (3%)	6 (2%)
Not applicable	63 (13%)	39 (27%)	24 (7%)

Values are expressed as No. (%).

BSA: Body surface area.