Inmaculada Hernandez

Risk of Bleeding With Dabigatran in Atrial Fibrillation

IMPORTANCE It remains unclear whether dabigatran etexilate mesylate is associated with higher risk of bleeding than warfarin sodium in real-world clinical practice. OBJECTIVE To compare the risk of bleeding associated with dabigatran and warfarin using Medicare data. DESIGN, SETTING, AND PARTICIPANTS In this retrospective cohort study, we used pharmacy and medical claims in 2010 to 2011 from a 5% random sample of Medicare beneficiaries. We identified participants as those newly diagnosed as having atrial fibrillation from October 1, 2010, through October 31, 2011, and who initiated dabigatran or warfarin treatment within 60 days of initial diagnosis. We followed up patients until discontinued use or switch of anticoagulants, death, or December 31, 2011. EXPOSURES Dabigatran users (n = 1302) and warfarin users (n = 8102). MAIN OUTCOMES AND MEASURES We identified any bleeding events and categorized them as major and minor bleeding by anatomical site. Major bleeding events included intracranial hemorrhage, hemoperitoneum, and inpatient or emergency department stays for hematuria, gastrointestinal, or other hemorrhage. We used a propensity score weighting mechanism to balance patient characteristics between 2 groups and Cox proportional hazards regression models to evaluate the risk of bleeding. We further examined the risk of bleeding for 4 subgroups of high-risk patients: those 75 years or older, African Americans, those with chronic kidney disease, and those with more than 7 concomitant comorbidities. RESULTS Dabigatran was associated with a higher risk of bleeding relative to warfarin, with hazard ratios of 1.30 (95% CI, 1.20-1.41) for any bleeding event, 1.58 (95% CI, 1.36-1.83) for major bleeding, and 1.85 (95% CI, 1.64-2.07) for gastrointestinal bleeding. The risk of intracranial hemorrhage was higher among warfarin users, with a hazard ratio of 0.32 (95% CI, 0.20-0.50) for dabigatran compared with warfarin. Dabigatran was consistently associated with an increased risk of major bleeding and gastrointestinal hemorrhage for all subgroups analyzed. The risk of major bleeding among dabigatran users was especially high for African Americans and patients with chronic kidney disease. CONCLUSIONS AND RELEVANCE Dabigatran was associated with a higher incidence of major bleeding (regardless of the anatomical site), a higher risk of gastrointestinal bleeding, but a lower risk of intracranial hemorrhage. Thus, dabigatran should be prescribed with caution, especially among high-risk patients.

Evaluating the Initiation of Novel Oral Anticoagulants in Medicare Beneficiaries

BACKGROUND As alternatives to warfarin, 2 novel oral anticoagulants (NOACs), dabigatran and rivaroxaban, were approved in 2010 and 2011 to prevent stroke and other thromboembolic events in patients with atrial fibrillation. It is unclear how patient characteristics are associated with the initiation of anticoagulants. OBJECTIVE To evaluate how patient demographics, clinical characteristics, types of insurance, and patient out-of-pocket spending affect the initiation of warfarin and 2 NOACs--dabigatran and rivaroxaban. METHODS We used pharmacy claims data from a 5% random sample of Medicare beneficiaries to identify patients who were newly diagnosed with atrial fibrillation between October 1, 2010, and October 31, 2012, and who were prescribed an oral anticoagulant within 60 days of diagnosis. We identified key predictors of initiation of NOACs using a multinomial logistic regression model with generalized logit link. RESULTS Patients who were black and who had a history of acute myocardial infarction, stroke or transient ischemic attack, chronic kidney disease, or congestive heart failure were significantly associated with lower odds of receiving NOACs compared with warfarin. Age greater than 65 years, a history of hypertension, and use of nonsteroidal anti-inflammatory drugs were positively associated with the initiation of NOACs. Rivaroxaban was most likely to be initiated among women, followed by warfarin and dabigatran. Individuals receiving a low-income subsidy were more likely to initiate warfarin than NOACs, even though they paid little copayment. Individuals with supplemental Part D drug coverage, such as national Programs for All-Inclusive Care for the Elderly or employer-sponsored plans, were more likely to initiate NOACs compared with warfarin. CONCLUSIONS We found that race, sex, type of Part D plans, and some clinical conditions were associated with the initiation of NOACs relative to warfarin. But patient demographic and clinical characteristics did not appear to affect which particular NOAC patients initiated.

Cost-effectiveness of non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with atrial fibrillation at high risk of bleeding and normal kidney function

INTRODUCTION The comparative cost-effectiveness of all oral anticoagulants approved up to date has not been evaluated from the US perspective. The objective of this study was to compare the cost-effectiveness of edoxaban 60mg, apixaban 5mg, dabigatran 150mg, dabigatran 110mg, rivaroxaban 20mg and warfarin in stroke prevention in atrial fibrillation patients at high-risk of bleeding (defined as HAS-BLED score≥3). MATERIALS AND METHODS We constructed a Markov state-transition model to evaluate lifetime costs and quality-adjusted life years (QALYs) with each of the six treatments from the perspective of US third-party payers. Probabilities of clinical events were obtained from the RE-LY, ROCKET-AF, ARISTOTLE and ENGAGE AF-TIMI trials; costs were derived from the Healthcare Cost and Utilization Project, and other studies. Because edoxaban is only indicated in patients with creatinine clearance ≤95ml/min, we re-ran our analyses after excluding edoxaban from the analysis. RESULTS Treatment with edoxaban 60mg cost

Anticoagulation Use and Clinical Outcomes After Major Bleeding on Dabigatran or Warfarin in Atrial Fibrillation

77,565/QALY gained compared to warfarin, and apixaban 5mg cost

Comparison of the Effectiveness and Safety of Apixaban, Dabigatran, Rivaroxaban, and Warfarin in Newly Diagnosed Atrial Fibrillation

108,631/QALY gained compared to edoxaban 60mg. When edoxaban was not included in the analysis, treatment with apixaban 5mg cost

Total Costs of Chimeric Antigen Receptor T-Cell Immunotherapy

84,128/QALY gained, compared to warfarin. Dabigatran 150mg, dabigatran 110mg and rivaroxaban 20mg were dominated strategies. CONCLUSIONS For patients with creatinine clearance between 50 and 95ml/min, apixaban 5mg was the most cost-effective treatment for willingness-to-pay thresholds (WTP) above

Exposure-Response Association Between Concurrent Opioid and Benzodiazepine Use and Risk of Opioid-Related Overdose in Medicare Part D Beneficiaries

115,000/QALY gained, and edoxaban 60mg was cost-effective when the WTP was between

Revisiting Outcomes–Based Pricing Propositions for the PCSK9 Inhibitor Evolocumab

75,000 and

Comparing clinical and economic outcomes of biologic and conventional medications in postmenopausal women with osteoporosis

115,000/QALY gained. For patients with creatinine clearance >95ml/min, apixaban 5mg was the most cost-effective treatment for WTP thresholds above

Effectiveness and Safety of Direct Oral Anticoagulants and Warfarin, Stratified by Stroke Risk in Patients With Atrial Fibrillation

80,000/QALY gained.