Supplementary Material for: Quality of life benefit and clinical predictors of complete skin clearance in psoriasis: a multicenter, prospective, real-world study

Background: Newer biologics, such as interleukin (IL)-17 inhibitors, make it possible to achieve complete skin clearance (CSC) in patients with moderate-to-severe psoriasis. However, the clinical meaningfulness and predictive factors of CSC in daily practice have not yet been fully investigated. Objective: The study was conducted to: firstly, assess the impact of CSC on Quality of life (QoL) improvements compared with treatment responses without clearance; secondly, identify clinical parameters as predictors of CSC response in psoriasis patients treated with ixekizumab. Methods: Patients attending 26 dermatology centers across china were recruited into this real-world setting between August 2020 and May 2022. Prospective cohort study in which response to ixekizumab was assessed using the Psoriasis Area and Severity Index (PASI) and Dermatology Quality of Life Index (DLQI). The absolute DLQI score and DLQI (0) response at weeks 12 were compared between groups achieving various levels of skin clearance. A stepwise logistic regression analysis was applied to identify which baseline clinical characteristics were predictive factors for CSC. Results: After 12 weeks of treatment, 226 of 511 (44.2%) patients achieved CSC, defined as 100% improvement in PASI score (PASI-100). A significantly higher proportion of patients with CSC versus almost clear skin (PASI90-99) achieved DLQI score of 0, corresponding the experience of no impairment on QoL (54.4% vs 37.7%, p= 0.001). Females patients were more likely than males to achieve CSC response (odds ratio [OR] =1.83; 95% confidence interval [CI]: 1.24-2.70), while previous biologic treatment (OR=0.43; 95% CI: 0.24-0.81) and joint affected (OR=0.61; 95% CI: 0.42-0.89) was significantly associated with less CSC response. Conclusions: This study highlights the fact that clinical parameters are important in determining CSC response in psoriasis. In daily practice, achieving CSC represents a clinically meaningful treatment goal, especially from the patient perspective.