Sequential Expansion of Comparative Effectiveness of Anticoagulants

Sequential Expansion of Comparative Effectiveness of Oral Anticoagulants: A Cohort Study

This cohort study is the sequential expansion of the comparative effectiveness study of oral anticoagulants and plans to identify initiators of oral anticoagulants using electronic claims data from a commercial insurance database to quantify associations between anticoagulant choice (warfarin and dabigatran) and the occurrence of selected outcomes in patients with non-valvular atrial fibrillation at risk for stroke.

Inclusion criteria:

• A recorded diagnosis of atrial fibrillation.
• Initiation of anticoagulant medication (dabigatran (or other new oral anticoagulants as they become available) or warfarin).
• At least 18 years of age on the date of anticoagulant initiation.
• Congestive Heart Failure, Hypertension, Age > 75, Diabetes Mellitus, Prior Stroke or Transient Ischemic Attack, Vascular Disease, Age 65-74, Sex Category (CHA2DS2-VASc) score at least 1

Exclusion criteria:

• Patients with missing or ambiguous age or sex information.
• Patients with evidence of valvular disease.
• Patients with less than 12 months enrolment preceding the date of anticoagulant initiation
• Patients with a dispensing of any oral anticoagulant during the 12 months preceding the date of anticoagulant initiation
• Patients with a nursing home stay during the 12 months preceding the date of anticoagulant initiation