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Evaluating the safety and effectiveness of non-vitamin K antagonist oral anticoagulants in the medicare population

Hernandez, Inmaculada (2016) Evaluating the safety and effectiveness of non-vitamin K antagonist oral anticoagulants in the medicare population. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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For decades, warfarin was the only oral anticoagulant available for the prevention of stroke and systemic embolism in atrial fibrillation. Since 2010, four non-vitamin K antagonist oral anticoagulant agents have gained Food and Drug Administration approval for this indication: dabigatran, rivaroxaban, apixaban and edoxaban.
Chapter 1 provides an introduction to the three research manuscripts that constitute this dissertation. It reviews the use of anticoagulation therapy in atrial fibrillation and especially the evidence on non-vitamin K antagonist oral anticoagulants.
Chapter 2 (Manuscript 1) is a retrospective cohort study that compares the risk of stroke and bleeding with rivaroxaban 20mg/dabigatran 150mg, and rivaroxaban 15mg/dabigatran 75mg. This study found no difference in the risk of stroke between dabigatran and rivaroxaban; however, rivaroxaban 20mg and rivaroxaban 15mg were associated with higher risk of thromboembolic events other than stroke, death, major bleeding, and any bleeding events than dabigatran 150mg and dabigatran 75mg.
Chapter 3 (Manuscript 2) evaluates the patterns of anticoagulation use after a first major bleeding on dabigatran or warfarin, and compares the thromboembolic and bleeding risk between post-hemorrhage treatment groups. In this study, post-hemorrhage resumption of anticoagulation with either dabigatran or warfarin was associated with increased survival and stroke-free survival, as compared to discontinuing anticoagulation. In addition, this paper revealed that the risk of recurrent major hemorrhage was higher with warfarin than dabigatran.
Chapter 4 (Manuscript 3) is a cost-effectiveness study that compares edoxaban 60mg, apixaban 5mg, dabigatran 150mg, dabigatran 110mg, rivaroxaban 20mg and dose-adjusted warfarin in the prevention of stroke in atrial fibrillation patients with high risk of bleeding, as defined by HAS-BLED score ≥3. This study found that, while apixaban 5mg was the most effective strategy, its incremental cost-effectiveness ratio when compared to edoxaban was slightly above the $100,000 per quality-adjusted life year threshold.
Public Health Significance
The investigations reported in this dissertation will guide clinicians in the prescription of the most appropriate anticoagulation agent according to the clinical characteristics of atrial fibrillation patients. This will ultimately lead to the prevention of strokes, the second leading cause of mortality worldwide, and bleeding events, the most common complication of anticoagulation therapy.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Hernandez, Inmaculadainh3@pitt.eduINH30000000201184986
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairZhang, Yutingytzhang@pitt.eduYTZHANG
Committee MemberSmith, Kenneth Jkjs8@pitt.eduKJS
Committee MemberSaba, Samirsfs3@pitt.eduSFS3
Committee MemberBrooks, Maria M.mbrooks@pitt.eduMBROOKS
Date: 9 September 2016
Date Type: Publication
Defense Date: 12 May 2016
Approval Date: 9 September 2016
Submission Date: 20 April 2016
Access Restriction: 3 year -- Restrict access to University of Pittsburgh for a period of 3 years.
Number of Pages: 136
Institution: University of Pittsburgh
Schools and Programs: School of Public Health > Health Policy & Management
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Anticoagulation; Atrial fibrillation; Hemorrhage; Non-vitamin K antagonist oral anticoagulants; Stroke; Warfarin.
Date Deposited: 09 Sep 2016 19:20
Last Modified: 01 Jul 2019 05:15


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