Inclusion Criteria:  Incident VTE diagnosis in an inpatient or outpatient setting between 1 Mar 2013 and 30 Jun 2019 Received anticoagulation therapy (all medication codes for anticoagulants approved for VTE in Korea; UFH, LMWH, warfarin, and NOACs) within 30 days of their VTE diagnosis (the index date will be defined as the date of treatment initiation with anticoagulants) Aged ≥18 years at index date  Exclusion Criteria:  Had a record of VTE diagnosis within the 12-month period prior to the index VTE encounter. Diagnosed with atrial fibrillation/flutter, mechanical heart valve replacement or mitral stenosis anytime prior to index date Had a record of Inferior Vena Cava filter anytime prior to index date Received anticoagulatory therapy within the 12-month period prior to index VTE encounter Prescribed two different anticoagulants on the same index date Had a record of pregnancy within the 9-month period prior to index date Had a record of active cancer within the past 6 months of period prior to index date