Development of a patient-reported outcome questionnaire for use in adults with moderate-to-severe plaque psoriasis: The Psoriasis Symptoms and Signs Diary

Background: Patients with psoriasis (PsO) suffer from a variety of symptoms. Tools are needed to assess PsO symptoms and signs from the patient's perspective. Objective: To develop a patient-reported outcome (PRO) measure to assess symptoms and signs in individuals with moderate-to-severe PsO. Methods: Face-to-face concept elicitation interviews were conducted with 20 subjects with moderate-to-severe plaque PsO. Results from the interviews, a literature review, and clinical input informed the development of the draft Psoriasis Symptoms and Signs Diary (PSSD). Three waves of face-to-face cognitive interviews (n = 19) were conducted to evaluate the clarity and relevance of the PSSD. Additional interviews (n = 5) were conducted to confirm its content. Results: The PSSD assesses severity of 5 symptoms (itch, pain, stinging, burning, skin tightness) and 6 observable signs (skin dryness, cracking, scaling, shedding or flaking, redness, bleeding) using 0-10 numerical ratings. Two versions with different recall periods (24 h and past 7 days) were developed. PsO patients found the PSSD to be clear and relevant. Limitations: The sample had limited racial diversity. Conclusion: The PSSD, developed according to the Food and Drug Administration PRO Guidance, assesses severity of symptoms and signs commonly associated with plaque PsO. Its measurement properties are currently being evaluated. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University.