Study looks at dabigatran adherence across Veterans Health Administration sites

Among patients with atrial fibrillation who filled prescriptions for the anticoagulant dabigatran at Veterans Health Administration sites, there was variability in patient medication adherence across sites, with appropriate patient selection and pharmacist-led monitoring associated with greater adherence to the medication, according to a study in the April 14 issue of JAMA.

Atrial fibrillation is the most common cardiac arrhythmia, affecting more than 3 million patients and necessitating treatment with oral anticoagulation in moderate- to high-risk patients to reduce stroke risk. Warfarin was the only treatment available until the recent introduction of target-specific oral anticoagulants (TSOACs), including dabigatran. Unlike warfarin, for which periodic laboratory testing is required, TSOACs do not require routine testing to evaluate anticoagulation effect. A previous study reported that suboptimal adherence to dabigatran was associated with increased risk of stroke and death, according to background information in the article.

Mintu P. Turakhia, M.D., M.A.S., of the VA Palo Alto Health Care System and Stanford University School of Medicine, and colleagues examined site-level variation in patient adherence to dabigatran and modifiable site-level practices associated with improved adherence in the Veterans Health Administration (VHA). The study included 67 VHA sites with 20 or more patients filling dabigatran prescriptions between 2010 and 2012 for nonvalvular atrial fibrillation (4,863 total patients; median, 51 patients per site), and also included 47 pharmacists from 41 eligible sites.

The median proportion of patients adherent to dabigatran was 74 percent, with variation in patient adherence across VHA sites. The authors write that the principal finding of their study was that appropriate patient selection was associated with better dabigatran adherence. Similarly, pharmacist-led monitoring (such as determining how medication was taken and stored, frequency of missed doses with timely laboratory testing) was associated with higher adherence with a progressive increase in adherence with longer duration of monitoring. In addition, pharmacist collaboration with clinicians for patients who were nonadherent was associated with higher adherence rates.

"These findings suggest that such site-level practices provide modifiable targets to improve patient adherence to dabigatran as opposed to patient characteristics that frequently cannot be modified."

"Our results highlight the importance of selecting patients and monitoring strategies to translate the efficacy of TSOACs in randomized trials to clinical practice. Prior studies have described variation in patient performance on warfarin across sites further highlighting the importance of management strategies in improving patient performance to anticoagulants," the researchers write. They add that the higher adherence rates associated with provision of dedicated monitoring even for a short time is potentially due to consistent contact made with patients.