INTRODUCTION: Psoriasis is a heterogeneous chronic inflammatory disease with multiple manifestations, which can affect the skin, nails, and joints. A wide selection of efficacious and safe biologic agents is available for the treatment of moderate to severe psoriasis. This study aimed to assess patients’ preferences amongst a selection of biologic treatment attributes for moderate to severe psoriasis in German patients.
METHODS: In this study, we estimated the relative importance of attributes of treatments for moderate to severe psoriasis using a web-based discrete-choice experiment (DCE) survey. Respondents were asked to choose hypothetical biologic treatments described by five attributes: number of patients achieving clear or almost clear skin after 1 year of treatment, number of times the medicine is taken in the first year, risk of mild to moderate injection site reactions (ISR) in the first year, risk of serious infection in the first year, and number of years studies have proven the medicine works with no changes in side effects. Each choice set had two hypothetical treatments with varying levels within attributes from which respondents selected. Preference weights measuring the strength of preference for an attribute level relative to other levels were estimated with random-parameters logit and used to calculate relative importance scores of each attribute. Additionally, in a separate series of direct questions, patients ranked the importance of the five attributes selected for the DCE study plus five additional psoriasis-related treatment attributes – effective in treating all manifestations of plaque psoriasis and psoriatic arthritis [PsA], complete relief of psoriasis symptoms, achieving clear or almost clear skin more quickly, risk of the medicine becoming less effective due to antidrug antibodies, and number of injections required each time the medicine is taken.
RESULTS: 300 patients with psoriasis (mean age: 47 years) completed the survey; 58% were male, 33% had prior experience with biologics, 35% had previously experienced an ISR, and 61% had self-reported PsA. According to the conditional relative importance scores, the risk of mild to moderate ISR was the most important attribute, followed by the number of people who have clear or almost clear skin (Figure 1). The other attributes had similar importance except that the number of years of proven efficacy and safety was more important than risk of serious infections (p<0.05). Numerically, the importance of ISR was 1.5 and 1.2 times higher than the importance of clear skin and of years of evidence for patients with ISR experience (p=0.143 and p=0.428, respectively). Whereas the importance of ISR was equivalent to the importance of clear skin (p=0.869) and ISR risk was 1.7 times more important than years of evidence among patients without ISR experience (p=0.001). When more attributes were added in the ranking exercise, patients ranked the treatment’s ability to also work on PsA and other manifestations of psoriasis as the most important attribute on average, before the risk of side effects and clear skin.
CONCLUSION: This study shows from the patient perspective the importance of drug effectiveness on multiple manifestations of psoriasis including PsA for psoriasis patients and avoidance of ISR. This may help conversations between patients and physicians about treatment decisions for moderate to severe psoriasis.
