To describe the rate of discontinuation among Non-Valvular Atrial Fibrillation (NVAF) patients who were on warfarin and have switched to the Novel oral anticoagulants(NOACs).

Inclusion Criteria:

• Individuals with NVAF who were on warfarin and have switched to the NOACs (dabigatran, rivaroxaban and apixaban) within the study period January 01, 2013 through March 31, 2014
• Individuals ≥18 years old on the index date
• At least 1 year of baseline period with history of continuous warfarin use in the baseline period for at least 3 months immediately before the index date
• At least 1 diagnosis of AF in the 12 months prior to index date
• Continuous eligibility with medical and pharmacy benefits for at least 12 months before the index date through 1 month after the index date

Exclusion Criteria:

• Individuals with a diagnosis of valvular heart disease or cardiac surgery during the 12 months prior to index date

The initial study population will include Non-valvular atrial fibrillation (NVAF) patients who initiated warfarin or Novel oral anticoagulants (NOACs) between January 01, 2012 and August 31, 2014. The date of the first NOAC prescription claim during the enrollment period will serve as the index date. The patients who have at least 1 year of baseline data available will be included in the study.