Essential Factors Influencing Health-Related-Quality of Life in Psoriasis
March 2014 | Volume 13 | Issue 3 | Original Article | 246 | Copyright © March 2014
Christine Rønneberg Mehren MD,a Anders Clemmensen MD,a Anne Boe-Hansen Dall MD,a
Peter Philipsen PhD,a and Robert Gniadecki MDa,b
aDepartment of Dermatology, Bispebjerg Hospital, Copenhagen, Denmark
bFaculty of Health Sciences, University of Copenhagen, Denmark
BACKGROUND: The negative impact of psoriasis on health related quality of life (HRQoL) has been well documented. An unanswered question is the relative contribution of different manifestations of psoriasis (skin, joint, nail involvement) to HRQoL.
AIM: To assess the relative contribution of the different symptom domains on HRQoL in psoriasis.
METHODS: 165 psoriasis patients (41.2 % with psoriasis arthritis (PsA)) were enrolled in a single-center cohort-study. For the assessment of HRQoL, patients completed EuroQoL (EQ-5D), the Short Form 36-item Health Survey (SF-36), the Health Assessment Questionaire (HAQ), and Dermatological Life Quality Index (DLQI) questionnaires. Multiple regression analysis was applied to determine the contribution of the measured parameters to the EuroQoL score (used as a reference measure for overall HRQoL).
RESULTS: Psoriasis arthritis (PsA) patients showed a higher impairment in all HRQoL measures than the patients without PsA. PASI, number of affected joints (PsA-score), DLQI and HAQ were significant predictors of HRQoL (R2=0.57). HAQ was the dominant contributor to HRQoL, both in patients with PsA and without PsA (partial eta 0.23 and 0.28, respectively.) Final model with improved R2 (0.61) was obtained by backward regression analysis, and included 6 parameters: PASI, PsA-score, and three questions from HAQ and one question from DLQI questionnaire.
CONCLUSION: Musculoskeletal symptoms are an essential component of HRQoL in psoriasis, even in patients without active PsA. A model consisting of PASI, PsA-score, and 4 questions derived from DLQI and HAQ seems to reflect total HRQoL impairment in psoriasis. This finding may further optimize drug therapy in psoriasis. J Drugs Dermatol.
The impairment of the health related quality of life (HRQoL) caused by psoriasis can be compared to other severe diseases such as ischemic heart disease, chronic obstructive pulmonary disease, and cancer.1 This impact has been studied mainly in relation to the cutaneous manifestations of the disease. However, the clinical manifestations of psoriasis may involve other organs and systems, mainly the joints (peripheral arthritis, spondylitis), tendons (enthesitis), or the periarticular connective tissue (dactylitis).2-5 Nail involvement is common among psoriasis patients, affecting 80% to 90% of psoriasis patients at some point in their lives.6 Over 50% of psoriasis-patients with nail involvement described pain as a symptom and experienced restrictions in their daily activities.7 Moreover psoriasis is associated with significant cardiovascular and psychological co-morbidities, which also contribute to the general impairment of HRQoL.8-11
The assessments instruments currently used in clinical practice
mainly focus on single symptomatic domains, such as joints or the skin. The important question is how the different
facets of the psoriatic disease contribute to the overall decrease in HRQoL in the patients. There is evidence that patients
with psoriasis arthritis (PsA) exhibit greater impairment of quality of life than the psoriasis patients without arthritis. The impact of the joint problems seems to be greater than that of the skin problems.4 The understanding of the relative contribution
of the different symptoms for HRQoL is very important, since it will allow to establish the treatment goals which are relevant for the patients.
In this study we measured the overall HRQoL using the Short Form 36-item Health Survey (SF-36), and EuroQoL (EQ-5D). We related the life quality impairment to the objective measures of disease activity (the Psoriasis Area and Severity
Index (PASI), number of tender and swollen joints, nail involvement) and organ-specific HRQoL (Dermatological Life Quality Index (DLQI), Health Assessment Questionnaire (HAQ)). The primary objective was to assess the relative contribution
of the different symptom domains of psoriasis into the total impairment of HRQoL.
MATERIALS AND METHODS
Design and Population
We designed a cross-sectional, non-interventional, single-centre study with the inclusion of patients with active chronic plaque psoriasis. A total of 165 patients participated in the study (Table 1). The diagnosis of psoriasis was confirmed by clinical examination. The patients were seen on a single visit between May 2009 and February 2010 in our Institution. Exclusion criteria included complete remission (ie, PASI=0), age>70, significant co morbidities which in the opinion of the patient and the investigator would affect the quality of