The purpose of this study is to evaluate and characterise the important identified and potential risks of upadacitinib and missing information on the safety of upadacitinib, as described in the EU RMP for upadacitinib for the treatment if AD. Primary objective: To describe and if possible compare the incidence of Malignancy (excluding NMSC) including malignancy by type, NMSC, MACE, VTE, serious infections (including OI), HZ, EH/ KVE, TB, GI perforations, DILI, fractures and all-cause mortality, in adolescent and adult individuals with AD treated with upadacitinib, relative to those treated with other selected systemic AD treatments. The secondary objectives are: To describe the incidence of the safety outcomes mentioned under primary objectives in upadacitinib users by: dose of upadacitinib (15 mg and 30 mg), age group (adolescents 12-17 years, 18-64 years, 65-74 years and ≥ 75 years) at the time of upadacitinib initiation, history of moderate hepatic impairment at the time of upadacitinib initiation, history of chronic infection with hepatitis B virus or hepatitis C virus at the time of upadacitinib initiation, and history of severe renal impairment at the time of upadacitinib initiation. If a suitable comparator is identified: To describe the incidence of the safety outcomes mentioned under primary objectives in adolescent and adult individuals with AD treated with other select systemic AD treatments by: age group (adolescents 12-17 years, 18-64 years, 65-74 years and ≥ 75 years) at the time of treatment initiation, history of moderate hepatic impairment at the time of treatment initiation, history of chronic infection with hepatitis B virus (HBV) or hepatitis C virus (HCV) at the time of treatment initiation, and history of severe renal impairment at the time of treatment initiation.