A study involving real-world database analysis to evaluate the hospital healthcare utilization and costs, and all-cause, major bleeding-, clinically relevant bleeding-, any bleeding-, and venous thromboembolism (VTE)-related hospital readmissions among hospitalized VTE patients treated with apixaban or warfarin, with or without low molecular weight heparin (LMWH)

Inclusion Criteria:

• Have a primary diagnosis of VTE identified by ICD-9-CM or ICD-10 codes from the Premier Hospital database between 01-Aug-2014 and 31-May-2016
• Age 18 years or older as of index hospitalization with VTE diagnosis
• Patients will be required to have received apixaban or warfarin with or without LMWH (index drugs) during the index hospitalizations

Exclusion Criteria:

• Received both apixaban and warfarin during the index hospitalization. This exclusion criterion will allow to cleanly group patients into the apixaban and warfarin usage cohorts.
• Received any other Direct oral anticoagulants (DOAC) including rivaroxaban, dabigatran, and edoxaban during the index hospitalization
• Have any primary or secondary diagnosis code for Atrial fibrillation/Atrial flutter (AF/AFL), or pregnancy, or records of inferior vena cava filter (IVCF) usage during the index hospitalizations or the baseline periods.
• Patients transferred from other facilities

Other protocol-defined inclusion/exclusion criteria could apply

The study population will include patients with a hospital or ED discharge International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) or ICD-10 code indicating a primary diagnosis of VTE identified from the Premier Hospital database between 01-Aug-2014 and 31-May-2016. Patients who received apixaban or warfarin with or without LMWH during any time of the hospitalization (from admission to discharge) will be identified. Patients receiving both apixaban and warfarin, or any other direct oral anticoagulant (DOAC), including rivaroxaban, dabigatran, and edoxaban, during the index hospitalizations will be excluded from the study population. Patients will be required to have no evidence of atrial fibrillation (AF) or atrial flutter (AFL) during the index hospitalizations or the baseline periods.