Assessing the burden of psoriasis on patients’lives: the Psodisk questionnaire

INTRODUCTION & OBJECTIVES: Patients with psoriasis and psoriatic arthritis have significant physical and psychosocial burden, experiencing, during life course, feelings of anger, frustration, helplessness, embarrassment, self-consciousness. The disease also has negative impact on sexual behavior and work productivity. Thus, the availability of patient-reported outcome (PRO) measures to assess patient symptoms is important in evaluating quality of life during treatment, improving compliance and clinical outcomes; nevertheless, regular assessments are not systematically performed in daily clinical practice, mainly for lack of time. Furthermore, many of these questionnaires are of difficult comprehension and time-expensive, both for compilation by patients and for interpretation of the results by physicians. Very recently, a new fast and intuitive instrument (Psodisk), taking into account different aspects of the burden of psoriasis on the patient, was developed to be used during the clinical interview, thus facilitating the communication between dermatologists and patients. The answers are given on a 10-point visual analogue scale and graphically represented on a disc as a polygon. The aim of our study was to evaluate the measurement properties of the Psodisk with respect to a validated method (Dermatology Life Quality Index) and its responsiveness to change in clinical status over-time following treatment for moderate-severe disease. MATERIAL & METHODS: Prospective study including 28 adult patients affected by psoriasis and/or psoriatic arthritis with PASI score > 10, candidates to start a biologic therapy. Patients were invited to complete Psodisk and DLQI at T0 (first administration of therapy) and every 12 weeks, at follow-up visits (T12, T24, T36, T48). PASI index was recorded as well. Psodisk construct validity was assessed using Spearman’s rank correlation between Psodisk and Dermatology Life Quality Index; the ability of Psodisk to detect change was determined using PASI improvement status. RESULTS: Validity was indicated by strong correlation between the Psodisk and Dermatology Life Quality Index scores. Responsiveness was demonstrated by statistically significant differences in mean change of Psodisk scores among groups of patients with different levels of improvement in the PASI. CONCLUSIONS: Psodisk represents a fast and valid instrument to measure the burden of psoriasis on patients’ life, suitable for routinary