Clinical Research Directory

Inclusion criteria: 1. Patients with at least one diagnosis of chronic urticaria during the study period. A chronic urticaria diagnosis is defined as including "chronic urticaria" but without any rule-out terms in the diagnosis name. 2. Patients treated with omalizumab during the identification period. The date of first omalizumab prescription is defined as the index date. 3. Patients aged 18 years or older at index. 4. Patients with at least one medical record ≥12 months prior to index date. Additional inclusion criterion for patients included in healthcare resource utilization (HCRU) outcomes: 5. Patients with at least one medical record ≥12 months post index date. Exclusion criteria: 1. Patients with a diagnosis of allergic asthma during the study period. 2. Patients without any dosing information (raw or derived) for omalizumab.