Identifying Factors That Predict the Prescription of Non–vitamin K Antagonist Oral Anticoagulants in Older Individuals With Atrial Fibrillation

Abstract Objectives Factors that influence decision of non–vitamin K antagonist oral anticoagulants (NOACs) use among older atrial fibrillation (AF) patients in long-term care (LTC) facilities have not been well studied. The aim of this study was to assess whether increased frailty influenced physicians to prescribe NOACs over warfarin. Design We retrospectively reviewed the electronic medical record (EMR) and pharmacy data of 25 LTC facilities in Ontario, Canada, in May 2015. The diagnosis of AF was ascertained from EMR and confirmed by complete chart review of a random sample of the cohort. A score of ≥2 on the Changes in Health, End-stage disease, Signs, and Symptoms (CHESS) scale was used as a surrogate marker of frailty. Measures Multivariable logistic regression model was used to assess whether a higher frailty score is associated with the use of NOACs in comparison to warfarin, independent of potential patient-level confounders. Setting and participants In total, 3378 active residents were assessed in 25 LTC facilities. All the residents were ≥65 years old. We identified 433 residents with AF; 273 (63%) AF residents were on anticoagulation therapy and included in the analysis. Results Residents were more often treated with NOACs (n = 159; 58%) in comparison to warfarin (n = 114; 42%). A CHESS score of ≥2 increased the odds of prescribing NOACs by 2.46 times [95% confidence interval (CI) 1.11, 5.49; P  = .03] when adjusted for important patient-level factors. Patients with hypertension had a trend of increased NOAC prescriptions but did not reach statistical significance [odds ratio 2.1 (95% CI 0.91, 4.81), P  = .08]. None of the patient-level factors were associated with NOAC prescriptions. Conclusions and Implications In this real world cohort of AF patients in LTC who are prescribed an oral anticoagulation therapy, a higher CHESS score (≥2) is associated with increased use of NOACs in comparison to warfarin.