Nail psoriasis as a severity indicator: results from the PsoReal study

Figures & data

Table 1 Characteristics of study population (n = 2449)

	n	%	Mean age ± SD (range 18–92)
Female	1078	44.8	57.0 ± 11.7
Male	1326	55.2	55.5 ± 12.0
Total^a	2404	100.0	57.0 ± 11.7
Partnership/marriage	1740	71.1	n.a.
Level of education
Without school completion certificate	9	0.4	n.a.
Secondary school	619	25.3	n.a.
Secondary modern school	738	30.1	n.a.
High school	990	40.4	n.a.
School for special education	2	0.1	n.a.
Other undefined education	48	2.0	n.a.
Working life
Employed	1289	52.7	n.a.
Not currently working	1159	47.3	n.a.
Current treatment
Biologics	190	7.8	n.a.
Systemic treatment	599	24.5	n.a.
Topical steroids	333	13.6	n.a.
Topical vitamin D3 analogs	323	13.2	n.a.
UV treatment	548	22.4	n.a.
PUVA treatment	71	2.9	n.a.
Topical skin care products	460	18.8	n.a.

Notes:

a Missing value for gender in 45 patients, missing value for age in 20 patients.

Abbreviations: PUVA, psoralen combined with ultraviolet A; UV, ultraviolet; n.a., not available; SD, standard deviation.

Table 2 Comparison between psoriasis patients with and without nail involvement (n = 2449)

Variable	No nail psoriasis			Nail psoriasis			P^c	d^d
	n	Mean	SD	Mean	SD	n
Years since initial diagnosis	607	33.0	16.1	34.3	13.9	1730	0.089	0.08
Affected body area (%)	621	5.5	11.1	8.3	14.9	1753	<0.001**	0.21
Quality of life (DLQI)	621	5.3	5.3	7.2	6.4	1761	<0.001***	0.33
EQ-5D: State of health (0–100)	611	67.3	21.0	60.1	21.6	1747	<0.001***	0.34
Number of inpatient treatments for psoriasis in previous 5 years	95	3.0	4.5	3.5	6.0	442	0.445	0.09
Days off work due to psoriasis in previous 12 months	339	3.3	15.9	9.8	42.0	936	<0.001*	0.2
PBI total score (weighted)	589	2.4	1.1	2.3	1.1	1671	0.004*	0.14
Satisfaction with previous psoriasis treatment^a	604	2.0	0.8	2.2	0.8	1722	<0.001*	0.21
Treatment regarded as a burden^b	511	1.8	1.2	2.1	1.2	1534	<0.001*	0.21
Treatment is associated with great time expenditure^b	509	1.7	1.3	1.9	1.3	1531	0.001*	0.17

Notes:

a (1 = very satisfied to 4 = very unsatisfied);

b (1 = not at all to 5 = very);

c level of significance in t-test for independent samples;

d effect size;

* significant after Bonferroni correction at the P < 0.05 level;

** highly significant after Bonferroni correction at the P < 0.01 level;

*** highly significant after Bonferroni correction at the P < 0.001 level.

Abbreviations: DLQI, Dermatology Life Quality Index; EQ-5D, Euroqol; PBI, patient-defined treatment benefit; SD, standard deviation.

Table 3 Frequency of consultations due to psoriasis (n = 2366)^a

	No nail psoriasis		Nail psoriasis		P^c
	Mean	SD	Mean	SD
Office visits in last 12 months
Dermatologist^b	1.7	1.3	2.0	1.4	<0.001*
Internal specialist^b	0.6	0.9	0.8	1.1	<0.001*
Orthopedic surgeon/rheumatologist^b	0.8	1.0	1.1	1.1	<0.001*
General practitioner^b	1.9	1.1	2.1	1.2	<0.001*

Notes:

a Data with regard to a therapist in those cases in which any office visit frequency was entered were counted as “no visits”; n = 52 (no entry regarding a doctor); n = 31 (no entry regarding nail involvement);

b within the last 12 months, 0 = no doctor visits, 1 = 1–2 times, 2 = 3–5 times, 3 = 6–10 times, 4 ≥ 10 times;

c due to the ordinal scaled variable a nonparametric Mann-Whitney U-test was calculated;

* still significant after Bonferroni correction.

Abbreviation: SD, standard deviation.