The Comparative Safety and Effectiveness of Warfarin and Dabigatran Utilized in the Department of Defense (DoD) Non-Valvular Atrial Fibrillation (NVAF) Patient Population-A Retrospective Database Analysis

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Drug utilisation

  Effectiveness study (incl. comparative)

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medicinal product name:
  PRADAXA
• Medicinal product name, other:
  Warfarin
• Medical condition to be studied:
  Atrial fibrillation

Population studied

• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Estimated number of subjects:
  28000

Study design details

• Main study objective:
  To assess the safety and effectiveness of dabigatran and warfarin in patients diagnosed with non-valvular atrial fibrillation in the DoD population.
• Outcomes:
  stroke (hemorrhagic, ischemic), major bleeding, Ischemic stroke, Hemorrhagic stroke, Major Intracranial bleeding, Major Extracranial bleeding (Major GI bleeding (upper and lower), Major Urogenital bleeding, Major Other bleeding), Transient ischemic attack (TIA), Myocardial infarction (MI),Venous thromboembolism (VTE, deep vein thrombosis DVT or pulmonary embolism PE), Death (all cause)
• Data analysis plan:
  Patients will be followed until OAC discontinuation/switch, disenrollment, death, or study end (whichever occurs first). Baseline characteristics for the study cohorts will be described and compared for the dabigatran (DE) and warfarin cohorts before and after propensity score matching (PSM). Inferential statistics will be used to analyze post-match differences between cohorts. For categorical variables, chi-square tests will be used, and for interval variables, t-tests or, if distribution is not normal, Wilcoxon rank sum test will be conducted. For the comparison of baseline characteristics before and after PSM, a conventional alpha of 0.05 and two-tailed level of significance will be used unless otherwise specified. To compare the occurrence of primary and secondary outcomes between DE and warfarin cohorts, time to event will be investigated using non-parametric Kaplan-Meier (KM) survival analyses. Cox proportional hazards models will be implemented if the PSM leaves imbalance.