Trends in Use of Oral Anticoagulants in Older Adults With Atrial Fibrillation

Quick Takes

  • Oral anticoagulants are increasingly prescribed for older adults with AF.
  • Older adults, especially those with dementia, frailty, and/or anemia, remain significantly undertreated for stroke prevention in AF.
  • Implementation efforts targeting stroke-prevention therapies for older adults with AF are needed.

Study Questions:

What are the trends in oral anticoagulant (OAC) initiation and nonadherence among older adults with atrial fibrillation (AF)?


The authors used the Optum administrative claims data from 2010–2020 to identify Medicare Advantage plan beneficiaries aged ≥65 years with AF. Included patients were assessed for comorbid dementia, frailty, and/or anemia. The co-primary outcomes were OAC initiation within 12 months of AF diagnosis and nonadherence to OAC use (<80% of proportional days covered per year).


The number of OAC-eligible older patients with AF per year ranged from 21,603–51,236 with a median age of 77.2 (standard deviation [SD], 6.1) to 77.4 (SD, 6.8) years and 51.8-49.8% were women. OAC initiation within 12 months after initial AF diagnosis increased from 20.2% in 2010 to 32.9% in 2020. Direct oral anticoagulant (DOAC) use increased from 1.1% in 2010 to 30.9% in 2020. OAC initiation was less likely among patients at an older age (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.98-0.98), with dementia (OR, 0.57; 95% CI, 0.55-0.58), with frailty (OR, 0.74; 95% CI, 0.72-0.76), and with anemia (OR, 0.75; 95% CI, 0.74-0.77). The median proportion of days covered increased from 77.6% (interquartile range [IQR], 41.0-96.4%) to 9.02% (IQR, 57.4-98.6%) and nonadherence decreased from 52.2% to 39.0%.


The authors concluded that OAC initiation in older adults has improved since the introduction of DOAC mediations but remains suboptimal, especially in patients with coexisting dementia, frailty, and anemia.


Several studies have demonstrated increased use of OAC for stroke prevention in AF since the introduction of DOAC medications. This study of older patients with Medicare Advantage insurance found similar trends, with nearly all patients being prescribed DOAC medications (as compared to warfarin) by 2020. However, overall use of OAC among older adults remains markedly low, with fewer than 50% receiving any OAC therapy. Use of OAC was even lower among those with ‘high-risk’ features, including dementia, frailty, and anemia. This represents a critical gap in evidence-based care, as older patients are among the highest risk for stroke prevention and several prior analyses have demonstrated favorable risk–benefit ratios. However, this claims-based analysis did not account for patients undergoing left atrial appendage occlusion, which may be a preferable option for many older patients at high risk for both stroke and bleeding. Furthermore, the nonadherence findings should be interpreted cautiously, as the proportion of days covered metric may not be accurate for warfarin given the highly variable dosing schedule. Nonetheless, this analysis confirms that older patients with AF remain vulnerable to untreated stroke risk. Prospective hybrid implementation-effectiveness studies exploring efforts to increase stroke-prevention methods (e.g., anticoagulation, left atrial appendage occlusion) are desperately needed.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Cardiovascular Care Team, Geriatric Cardiology, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Sleep Apnea

Keywords: Aged, Anemia, Anticoagulants, Arrhythmias, Cardiac, Atrial Appendage, Atrial Fibrillation, Dementia, Evidence-Based Medicine, Frailty, Geriatrics, Risk Assessment, Secondary Prevention, Stroke, Vascular Diseases, Warfarin

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