Patterns of Initiation of Oral Anticoagulants in Patients with Atrial Fibrillation— Quality and Cost Implications

doi:10.1016/j.amjmed.2014.05.013

The American Journal of Medicine

Volume 127, Issue 11, November 2014, Pages 1075-1082.e1

https://doi.org/10.1016/j.amjmed.2014.05.013 Get rights and content

Abstract

Background

Dabigatran, rivaroxaban, and apixaban have been approved for use in patients with atrial fibrillation based upon randomized trials demonstrating their comparable or superior efficacy and safety relative to warfarin. Little is known about their adoption into clinical practice, whether utilization is consistent with the controlled trials on which their approval was based, and how their use has affected health spending for patients and insurers.

Methods

We used medical and prescription claims data from a large insurer to identify patients with nonvalvular atrial fibrillation who were prescribed an oral anticoagulant in 2010-2013. We plotted trends in medication initiation over time, assessed corresponding insurer and patient out-of-pocket spending, and evaluated the cumulative number and cost of anticoagulants. We identified predictors of novel anticoagulant initiation using multivariable logistic models. Finally, we estimated the difference in total drug expenditures over 6 months for patients initiating warfarin versus a novel anticoagulant.

Results

There were 6893 patients with atrial fibrillation that initiated an oral anticoagulant during the study period. By the end of the study period, novel anticoagulants accounted for 62% of new prescriptions and 98% of anticoagulant-related drug costs. Female sex, lower household income, and higher CHADS₂, CHA₂DS₂-VASC, and HAS-BLED scores were significantly associated with lower odds of receiving a novel anticoagulant (P <.001 for each). Average combined patient and insurer anticoagulant spending in the first 6 months after initiation was more than $900 greater for patients initiating a novel anticoagulant.

Conclusions

This study demonstrates rapid adoption of novel anticoagulants into clinical practice, particularly among patients with lower CHADS₂ and HAS-BLED scores, and high health care cost consequences. These findings provide important directions for future comparative and cost-effectiveness research.

Section snippets

Study Population and Data Source

We used nationwide medical and prescription claims data from commercial patients covered by Aetna, a large health care benefits company, to create a cohort of patients with newly diagnosed nonvalvular atrial fibrillation who were prescribed an oral anticoagulant between October 1, 2010 and June 30, 2013.

These data contained complete paid claims data for all procedures, physician encounters, hospitalizations, and filled prescriptions (including dose dispensed and amounts paid by the insurer and

Results

The study cohort consisted of 6893 patients with nonvalvular atrial fibrillation newly initiated on an oral anticoagulant between October 1, 2010 and June 30, 2013 (Appendix, available online). Patients had a mean age of 61.3 years, were predominantly male (72.8%), and had mean CHADS₂ and HAS-BLED scores of 1.7 and 2.0, respectively (Table 1). Approximately one third of patients had a history of coronary artery disease, and one quarter had diabetes. Heart failure, renal dysfunction, or history

Discussion

This study of a contemporary cohort of patients with atrial fibrillation starting oral anticoagulant therapy demonstrates rapid adoption of novel anticoagulants into clinical practice, utilization associated with lower CHADS₂ and HAS-BLED scores, and significant health care cost implications. This study is the first, to our knowledge, to evaluate real-world use of all novel anticoagulants currently on the market.⁶

We observed a significant decline in the proportion of patients with atrial

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Vitamin K antagonists, warfarin in particular, have been the mainstay of anticoagulation therapy, but their use has declined in many countries since direct oral anticoagulants (DOACs) have entered the market.
To examine utilization trends of oral anticoagulants (OACs) in Finland considering the reimbursement of DOACs and changes to national treatment guidelines for the treatment of atrial fibrillation (AF).
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Citation Excerpt :
We included patients if they had at least one inpatient or outpatient diagnosis of atrial fibrillation in the 6 months prior to cohort entry and excluded patients with any alternate indication for anticoagulation, including deep vein thrombosis, pulmonary embolism, prosthetic heart valve, mitral valve stenosis, and hip or knee replacement surgery. All clinical exclusion and inclusion criteria were defined using a combination of International Classification of Diseases (ICD) codes, current procedural terminology codes, and Word Health Organization Anatomical Therapeutic Chemical classification system codes (Supplementary Table 1).1,11,28-31 Though the claims database included Medicare Advantage patients, we limited our cohort to commercially insured patients, since patients in Medicare prescription drug plans include a phased benefit design such that out-of-pocket costs for the first prescription depend on cumulative annual prescription drug spending and may not reflect ongoing out-of-pocket costs.
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: Funding: This work was funded by an unrestricted research grant from CVS Caremark to Brigham and Women's Hospital.

: Conflicts of Interest: None.

: Authorship: All authors had access to the data and played a role in writing this manuscript.

View full text

Clinical research studyPatterns of Initiation of Oral Anticoagulants in Patients with Atrial Fibrillation— Quality and Cost Implications

Abstract

Background

Methods

Results

Conclusions

Section snippets

Study Population and Data Source

Results

Discussion

Chest

Chest

Am J Cardiol

Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials

Arch Intern Med

Persistence with therapy among patients treated with warfarin for atrial fibrillation

Arch Intern Med

Dabigatran versus warfarin in patients with atrial fibrillation

N Engl J Med

Rivaroxaban versus warfarin in nonvalvular atrial fibrillation

N Engl J Med

Apixaban versus warfarin in patients with atrial fibrillation

N Engl J Med

National trends in oral anticoagulant use in the United States, 2007 to 2011

Circ Cardiovasc Qual Outcomes

Early adoption of dabigatran and its dosing in US patients with atrial fibrillation: results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation

J Am Heart Assoc

Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation

JAMA

Clinical research study
Patterns of Initiation of Oral Anticoagulants in Patients with Atrial Fibrillation— Quality and Cost Implications