Patient and Physician Preferences for Therapy Characteristics for Psoriasis: A Discrete Choice Experiment in Japan

Background With progress being made in the treatment of psoriasis, a variety of clinical research and treatment options are being pursued. This study used a discrete choice experiment (DCE) to estimate treatment characteristic preferences for both patients and physicians in Japan. Subgroup analysis was also applied in order to examine differences within the range of patients and within the range of physicians. Methods The DCE was developed with the input of clinical experts in the treatment of psoriasis to ensure inclusion of the most relevant attributes at appropriate levels in a way that is understandable to both physicians and patients. The study was conducted on parallel samples of Japanese physicians (n = 161) and Japanese psoriasis patients (n = 306) through an online panel. For each sample, a conditional logit statistical model and subgroup analysis were then performed to estimate respondent preferences for treatment attributes. Results The overall findings are that better treatment efficacy as measured by proportion of patients achieving 90% reduction in the Psoriasis Area and Severity Index score (PASI 90), lower risk of adverse events and the availability of a bio-holiday are important decision factors for both patients and physicians. Low injection frequency is less of a priority for both samples. Also, while both groups demonstrate a preference to receive the treatment injections at a clinic by a healthcare professional rather than self-injection at home, this is more pronounced for the patient sample. The physician sample shows considerably more emphasis on the type of injection, though both samples prefer subcutaneous injections to intravenous injections. Implications This study reveals the importance of addressing both clinical effectiveness and process factors in systemic, non-topical psoriasis treatments to gain acceptance by both physicians and patients. As well as efficacy (as measured by PASI 90), which remains a consistent priority in treatment, administration and development of new treatments should also consider process factors such as the mode of administration and possibility for a bio-holiday.