A Study to Describe the Real-world Effectiveness, Safety and Patterns of Use of Dupilumab in Patients With Chronic Spontaneous Urticaria

Sociodemographic and clinical characteristics, including but not limited to month and year of birth, age, sex, race, ethnicity, IgE levels, employment status, height, weight, and smoking status will be collected.

Medical history of CSU, including but not limited to CSU status and CSU treatment history will be collected.

Type of baseline comorbidities including atopic and non-atopic will be collected.

Type of concomitant medication will be collected.

Healthcare practitioner's information (related to CSU treatment) and specialty (example, dermatology physician, dermatology nurse practitioner, dermatology physician assistant, allergy/immunology physician, allergy/immunology nurse practitioner, allergy/immunology physician assistant) will be collected.

Summary of dupilumab dosing regimen, duration of treatment, time to discontinuation and other discontinuation details, and treatment modifications/interruptions and reasons will be collected.

Summary of treatments used after discontinuation will be collected.

Summary of participants re-treated with dupilumab and reason will be collected.

Change from baseline in disease activity as assessed by Urticaria Activity Score over 7 days (UAS7) and Urticaria Control Test (UCT) scores.

Summary of participants who achieve response thresholds, including onset of response, peak response, recapture response will be collected to evaluate the real-world long-term effectiveness of dupilumab for the treatment of CSU.

Summary of participants who achieve disease control thresholds will be collected to evaluate the real-world long-term effectiveness of dupilumab for the treatment of CSU.

Durability of response will be assessed by using Urticaria Activity Score over 7 days (UAS7). It is based on scoring wheals (hive severity score) and itch (itch severity score) separately on a scale of 0 (no signs/symptoms) to 3 (intense signs/symptoms) over 7 days. The final score is calculated by adding together the daily scores, which can range from 0 to 6, for 7 days. This results in a maximum total score of 42, and a minimum possible score of 0.

Duration of disease control prior to and after discontinuation of dupilumab will be assessed.

The CU-Q2oL is a patient-reported outcome measure designed to assess the impact of chronic urticaria on various aspects of a patient's life. It includes questions that evaluate physical symptoms, emotional well-being, daily activities, sleep quality, and treatment satisfaction. Responses are scored on a 5-point Likert scale, reflecting the overall QoL impairment, with higher scores indicating greater negative impact.

The DLQI is a 10-question, patient-reported outcome measure designed to assess the impact of skin diseases on the QoL.24 It covers domains such as symptoms, emotional well-being, leisure activities, school performance, personal relationships, and treatment burden. Each question is scored from 0 to 3, with a total score ranging from 0 to 30, where higher scores indicate greater impairment.

The CDLQI is a 10-question, patient-reported outcome measure designed to assess the impact of skin diseases on the QoL.24 It covers domains such as symptoms, emotional well-being, leisure activities, school performance, personal relationships, , and treatment burden. Each question is scored from 0 to 3, with a total score ranging from 0 to 30, where higher scores indicate greater impairment.

The WPAI:CU is a 6-item PRO instrument that measures the effect of a condition on productivity during work and regular activities in the 7 days prior to completion. The instrument comprises 4 domains: absenteeism, presenteeism, overall work impairment, and activity impairment due to chronic urticaria. WPAI:CU outcomes are expressed as impairment percentages, with higher numbers indicating greater impairment and less productivity.

The TSQM-9 is a 9-item PRO measure designed to evaluate satisfaction with medication across 3 domains: effectiveness, side effects, and convenience.27 It uses a 5- or 7-point Likert scale to score responses, which are then transformed to a 0-100 scale, with higher scores indicating greater satisfaction.

CSU-related hospitalization including number of hospital visits, number of emergency department visits, number of specialist visits will be collected.

Number of participants experiencing AEs will be assessed.

Number of participants experiencing SAEs will be assessed.

Number of participants experiencing AESI will be assessed.