NOAC Portuguese Real World Study

Inclusion Criteria: * Age ≥18 years on the index date. * At least 1 OAC (apixaban, dabigatran, rivaroxaban, VKAs) dispensed during the identification period. Exclusion Criteria: * Specialty of the physician responsible for the OAC prescription in the index date is one of the following: orthopedics, general surgery, vascular surgery or any other surgical specialty; * Duration of OAC therapy during follow-up inferior to the cut-off defined during the feasibility assessment (except if the patient was admitted to in-hospital care during follow-up); * The OAC dispensed in the index date was one of the following: dabigatran 75 mg or rivaroxaban 10 mg * Hospital claims lacking a diagnosis code indicative of AF during the study period; * Hospital claim indicating a diagnosis or procedure code indicative of pregnancy or childbirth during the study period; * Hospital claim indicating a diagnosis or procedure code indicative of valvular heart disease, venous thromboembolism, cardiac surgery, pericarditis, hyperthyroidism and thyrotoxicity during the baseline period; * Hospital claim indicating a diagnosis or procedure code indicative of hip and knee replacement surgery during the 6 weeks prior to the index date. Patients with past use of OAC will be excluded. Therefore, patients meeting any of the following criteria will be excluded: * Had any OAC (apixaban, dabigatran, edoxaban, rivaroxaban, VKAs) dispensed during the 12-month baseline period; * Had \>1 OAC dispensed on the index date.