The Utilization of Antithrombotic Therapy in Older Patients in Aged Care Facilities With Atrial Fibrillation

Abstract

Oral anticoagulants are essential drugs for the prevention of thromboembolic events in patients with atrial fibrillation (AF). Anticoagulants are, however, commonly withheld in older people due to the risk and fear of hemorrhage. Although the underutilization of anticoagulants in patients with AF has been demonstrated internationally, few studies have been conducted among aged care residents. The aim of this study was to determine the utilization of anticoagulants among people with AF residing in aged care facilities. We performed a non-experimental, retrospective analysis designed to evaluate antithrombotic usage in patients with AF in Australia residing in aged care facilities, using data collected by pharmacists while performing Residential Medication Management Reviews (RMMRs). The utilization of antithrombotic therapy and the appropriateness of therapy were determined based on the CHADS2, CHA2DS2-VASc, and HAS-BLED risk stratification schemes in consideration of documented contraindications to treatment. Predictors of anticoagulant use were determined using multivariate logistic regression. A total of 1952 RMMR patients with AF were identified. Only 35.6% of eligible patients (CHADS2 score ≥2 and no contraindications to anticoagulants) received an anticoagulant. As age increased, the likelihood of receiving an anticoagulant decreased and the likelihood of receiving an antiplatelet or no therapy increased. In patients at high risk of stroke (CHADS score ≥2), utilization of anticoagulants dropped by 19.7% when the HAS-BLED score increased from 2 to 3, suggesting that physicians placed a heavier weighting on bleeding risk rather than stroke risk. Prescribing of anticoagulants was influenced to a greater extent by bleeding risk than it was by the risk of stroke. Further research investigating whether the growing availability of direct oral anticoagulants influences practice in this patient population is needed.