Contemporary clinical and economic outcomes among oral anticoagulant treated and untreated elderly patients with atrial fibrillation: Insights from the United States Medicare database

Muhammad Bilal Munir,Cristina Russ,Huseyin Yuce,Matthew Cato,Jonathan C Hsu,Birol Emir,Mauricio Ferri,Jennifer D Guo,Patrick Hlavacek,Allison Keshishian,Rajesh Mallampati

doi:10.1371/journal.pone.0263903

Abstract

BackgroundOral anticoagulants (OACs) mitigate the risk of stroke in atrial fibrillation (AF) patients.ObjectiveElderly AF patients who were treated with OACs (apixaban, dabigatran, edoxaban, rivaroxaban, or warfarin) were compared against AF patients who were not treated with OACs with respect to their clinical and economic outcomes.MethodsNewly diagnosed AF patients were identified between January 2013 and December 2017 in the Medicare database. Evidence of an OAC treatment claim on or after the first AF diagnosis was used to classify patients into treatment-defined cohorts, and these cohorts were further stratified based on the initial OAC prescribed. The risks of stroke/systemic embolism (SE), major bleeding (MB), and death were analyzed using inverse probability treatment weighted time-dependent Cox regression models, and costs were compared with marginal structural models.ResultsThe two treatment groups were composed of 1,421,187 AF patients: OAC treated (N = 583,350, 41.0% [36.4% apixaban, 4.9% dabigatran, 0.1% edoxaban, 26.7% rivaroxaban, and 31.9% warfarin patients]) and untreated (N = 837,837, 59.0%). OAC-treated patients had a lower adjusted risk of stroke/SE compared to untreated patients (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.68–0.72). Additionally patients receiving OACs had a lower adjusted risk of death (HR: 0.56; 95% CI: 0.55–0.56) and a higher risk of MB (HR: 1.57; 95% CI: 1.54–1.59) and this trend was consistent across each OAC sub-group. The OAC-treated cohort had lower adjusted total healthcare costs per patient per month ($4,381 vs $7,172; p < .0001).ConclusionFor the OAC-treated cohort in this elderly US population, stroke/SE and all-cause death were lower, while risk of MB was higher. Among OAC treated patients, total healthcare costs were lower than those of the untreated cohort.

Highlights

Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice with an estimated US prevalence of 700–775 per 100,000 in the year 2010 [1]
The two treatment groups were composed of 1,421,187 atrial fibrillation (AF) patients: Oral anticoagulants (OACs) treated (N = 583,350, 41.0% [36.4% apixaban, 4.9% dabigatran, 0.1% edoxaban, 26.7% rivaroxaban, and 31.9% warfarin patients]) and untreated (N = 837,837, 59.0%)
The adjusted risk of major bleeding was higher in AF patients on OAC treatment compared to AF patients who were not treated with an OAC

Summary

Methods

This was a retrospective cohort study conducted using the United States Centers for Medicare & Medicaid Services (CMS) fee-for-service Medicare database from January 2012 until December 2017. After IPTW, the multivariable time-varying cox proportional hazard models were used to assess the risk of stroke/SE, major bleeding, and mortality comparing the treatment group of interest with the OAC untreated group being the reference In these hazard models, there were three time-varying variables, OAC treatment (a patient could change from the untreated to any one of the treated cohort subtypes), and CHA2DS2-VASc and modified HAS-BLED scores. OAC treated patients had significantly lower all-cause healthcare costs PPPM compared to OAC untreated patients ($4,381 vs $7,172; p

Results

Introduction

Discussion