Oral Anticoagulants Initiation in Patients with Atrial Fibrillation: Real-World Data from a Population-Based Cohort.

Clara L Rodríguez-Bernal,Isabel Hurtado,Salvador Peiró,Gabriel Sanfélix-Gimeno,Aníbal García-Sempere

doi:10.3389/fphar.2017.00063

Abstract

Objective: Little is known about initial prescription of currently used oral anticoagulants (OAC), and correlated characteristics in real-world practice. We aimed to assess patterns of initiation of Vitamin K antagonists (VKA) and non-VKA oral anticoagulants (NOAC) in naive patients with non-valvular atrial fibrillation and the factors associated with starting treatment with NOAC.Methods: Population-based retrospective cohort study of all patients with NVAF who had a first prescription of OAC from November 2011 to February 2014 in the Valencia region, Spain (n = 21,881). Temporal trends of OAC initiation are described for the whole population and by type of OAC and therapeutic agent. Factors associated with starting treatment with NOAC (vs. VKA) were identified using logistic multivariate regression models.Results: Among the patients initiating OAC, 25% started with NOAC 2 years after market release. Regarding temporal trends, prescription of NOAC doubled during the study period. VKA prescription also increased (by around 13%), resulting in a 30% rise in total treatment initiation with OAC during 2011–2014. NOAC initiation (vs. VKA) was associated with a lower baseline risk of thromboembolism and higher income.Conclusions: In this Spanish population-based cohort, initiation of OAC therapy saw a rapid increase, mainly but not exclusively, due to a two-fold rise in the use of NOAC. Initiation with NOAC was associated with a lower baseline risk of thromboembolism and higher income, which opposes the indications of NOAC use and reflects disparities in care. Inadequate prescription patterns might threaten the effectiveness and safety of these therapies, thus monitoring OAC prescription is necessary and should be setting-specific.

Highlights

Drug prescription to naïve patients—initial prescription—is the starting point for establishing treatment adequately, and provides an important opportunity to engage patients in therapy
The current—and ongoing—assessment of initiation patterns and factors related to them might provide useful insights into the appropriateness of initial prescription according to approved indications, as well as data that can be used for posterior surveillance or to study adequately comparative effectiveness in real world practice. To address this global knowledge gap, we aimed to describe the patterns of prescription of oral anticoagulants (VKA and non-VKA oral anticoagulants (NOAC)) as a starting treatment in naïve patients with nonvalvular atrial fibrillation, and to study factors associated with treatment initiation with NOAC in a large Spanish populationbased cohort
The study was set in the Valencia region and, in the population covered by the Valencia Health System (VHS), the public health system covering about 97% of the region’s population (≈5 million inhabitants)

Summary

Introduction

Drug prescription to naïve patients—initial prescription—is the starting point for establishing treatment adequately, and provides an important opportunity to engage patients in therapy. Oral anticoagulation (OAC) significantly reduces the risk of stroke in patients with atrial fibrillation when used adequately (1990; 1991; 1994; Petersen et al, 1989; Lancaster et al, 1991). NOAC have some theoretical advantages over VKA such as the scarcity of interactions, predictable effects with fixed dosages and no need for monitoring. They have significant limitations, including the unavailability of tests for monitoring their anticoagulant effectiveness, the low availability of antidotes to reverse their effect, and renal clearance.

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Results

Discussion

Conclusion