The overall objective of this proposal is to execute a real-world database analysis to evaluate hospital readmissions among hospitalized nonvalvular atrial fibrillation (NVAF) patients in the U.S

Primary objective: To determine the proportions of NVAF patients with bleeding-related hospital readmissions that occur within 30 days of the hospitalization of NVAF patients treated with the new oral anticoagulants (NOACs), dabigatran, rivaroxaban, apixaban or warfarin in the inpatient setting

Secondary objectives:

• To determine the cost associated with bleeding-related hospital readmissions that occur within 30 days of the hospitalization of NVAF patients treated with dabigatran, rivaroxaban, apixaban or warfarin in the inpatient setting
• To determine the proportions of NVAF patients with all cause hospital readmissions and the associated costs that occur within 30 days of the hospitalization of NVAF patients treated with dabigatran, rivaroxaban, apixaban or warfarin in the inpatient setting.

Inclusion Criteria:

• Have a primary or secondary diagnosis of AF identified by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes from the Premier Hospital database between January 1, 2012 and December 31, 2013
• Age 18 years or older as of initial hospitalization with AF diagnosis

Exclusion Criteria:

• Have any primary or secondary diagnosis code or procedure code for valvular disease during the study period. This exclusion criterion is consistent with that used in other previous BMS HEOR studies and is used to ensure that the study populations are NVAF patients
• Received multiple types of NOACs during the index hospitalization. Preliminary analysis showed that very few patients receive multiple types of new oral anticoagulants (NOACs) during the same hospitalization. This exclusion criterion will allow to cleanly group patients into the different NOAC usage groups

Premier Hospital database is the source of all data