Evaluation of the Sensitivity and Specificity of a Novel Quality of Life Tool to Assess the Treatment Satisfaction in Psoriasis Patients

The severity of psoriasis can be influenced by a great variety of factors including extent of the disease, lesions location and impact on quality of life. The current standard of care for psoriasis is focusing on the reduction of the skin symptoms as defined by the PASI, somewhat setting asides the patient's feelings in terms of which aspects of his/her life are affected by the disease. Despite the fact that multiple patient reported outcomes (PRO) questionnaires are available to evaluate the impact of the disease on patients' quality of life, only few items address the subjective impact of skin disease. Among the available PROs the Dermatology Life Quality Index (DLQI) is the most frequently used. It is a standardized tool designed to cover a broad range of dermatologic afflictions but lacks specificity towards the effect of psoriasis on quality of life. The DLQI is composed of ten questions grouped in 6 domains "symptoms and feelings", "daily activities", "leisure", "work/school", "personal relationships" and "treatment". Each answer is graded from 0 to 3. The DLQI score is calculated by adding the score of each question, resulting in a maximum score of 30 and a minimum of 0. The higher the score, the more quality of life is impaired. A score higher than 10 indicates that the patient's life is being severely affected by their skin disease.

Because of its limitations, some patients cannot seem to completely restore a normal quality of life (e.g. DLQI 0-1) even though their reached a perfect PASI score (100). This phenomenon may be explained by the fact that the patient's own perception can be different from the physician's perspective and may have changed in time, between follow-ups. These are as many reasons as why it is highly difficult to accurately fathom the therapeutic expectations of the psoriasis patients. The standard tools currently in use are not able to assess the perception of the disease by the patient its evolution over time. In addition, it is widely recognized that alexithymia is more prevalent in the psoriasis patients than in the general population and patients with alexithymia appear to suffer higher psoriasis burden as they have more difficulties to express their expectations. Since patients struggle to recognize and verbalize their emotions, it can be useful and informative to offer patients a variety of verbatim in which they can identify. PSO-TARGET is an exploratory observational, non-interventional study aiming to evaluate a novel approach of assessing psoriasis patients' satisfaction towards their biologic treatment from a quality of life standpoint by using a psoriasis-specific Quality of Life assessment grid.

The aim of this exploratory study is to evaluate the sensitivity and specificity of the PSO-TARGET QoL Component grid as part of a new approach for assessing the level of achievement of the psoriasis patient's therapeutic goal, identified by himself, after a treatment with Kyntheum®.