Does Race/Ethnicity Affect Oral Anticoagulant Use in Patients With Atrial Fibrillation? Findings From the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II

A study by Essien and his colleagues published in JAMA aimed to determine if there were racial/ethnic differences in the use of oral anticoagulants, particularly direct-acting oral anticoagulants (DOACs), in patients with atrial fibrillation. The findings showcased the fact that after controlling for clinical and socioeconomic factors, black individuals were less likely than white individuals to receive DOACs for atrial fibrillation, with no difference between white and Hispanic groups.

The study is important because black and Hispanic patients are less likely than white patients to use oral anticoagulants for atrial fibrillation. However, little is known about racial/ethnic differences in use of direct-acting oral anticoagulants (DOACs) for atrial fibrillation. Therefore, the investigators used data from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II, a prospective, US-based registry of outpatients with nontransient AF 21 years and older who were followed up from February 2013 to July 2016. Data were analyzed from February 2017 to February 2018. Self-reported race/ethnicity was categorized as white, black, or Hispanic. The primary outcome was the use of any OAC, particularly DOACs. Secondary outcomes included the quality of anticoagulation received and OAC discontinuation at 1 year. A multivariable logistic regression model with the site as a random effect was used to evaluate the association between race/ethnicity and overall OAC use at baseline.

Of a total of 12,417 patients, 11,100 were white individuals (88.6%), 646 were black individuals (5.2%), and 671 were Hispanic individuals (5.4%) with atrial fibrillation. Moreover, after adjusting for clinical features, black individuals were less likely to receive any OAC as compared to white individuals (adjusted odds ratio [aOR], 0.75; 95% confidence interval [CI], 0.56-0.99) and less likely to receive DOACs if an anticoagulant was prescribed (aOR, 0.63; 95% CI, 0.49-0.83). Interestingly, after further controlling for socioeconomic factors, OAC use was no longer significantly different in black individuals (aOR, 0.78; 95% CI, 0.59-1.04); among patients using OACs, DOAC use remained significantly lower in black individuals (aOR, 0.73; 95% CI, 0.55-0.95). There was no significant difference between white and Hispanic groups in use of OACs. Among patients receiving warfarin, the median time in therapeutic range was lower in black individuals (57.1%; interquartile range [IQR], 39.9%-72.5%) and Hispanic individuals (51.7%; IQR, 39.1%-66.7%) than white individuals (67.1%; IQR, 51.8%-80.6%; p < 0.001). Black and Hispanic individuals treated with DOACs were more likely to receive inappropriate dosing than white individuals (black patients, 61 of 394 [15.5%]; Hispanic patients, 74 of 409 [18.1%]; white patients, 1,003 of 7,988 [12.6%]; p = 0.01). One-year persistence on OACs was the same across groups.

Thus, in this multicenter US-based registry study of a cohort of 12,147 outpatients with atrial fibrillation, black patients were significantly less likely to receive direct-acting oral anticoagulants than white patients, even after controlling for clinical and sociodemographic features; no difference between white patients and Hispanic patients was observed. Dr. Essien believed that reducing disparities in stroke prevention for patients with atrial fibrillation may improve the overall quality of care and result in reduced complication rates. Interpreting the results of the study, he remarked, “There have been several possible reasons proposed to explain racial/ethnic disparities in AF management. First, limited access to specialists in minority populations has been described and remains an important target of interventions to reduce disparities. Second, out-of-pocket costs for DOACs may be a greater barrier to their use among patients in lower socioeconomic brackets.  A detailed assessment of the respective roles and preferences of patients and physicians in the anticoagulation decision is merited.”