Involving pharmacists may boost adherence to NOACs

The trick to medication adherence may be to shift the focus from patient to provider. At least in the case of dabigatran, modifiable practices at Veterans Affairs sites appeared to make a difference in whether patients with atrial fibrillation took their anticoagulant most of the time.

In a study published in the April 14 issue of JAMA, Supriya Shore, MD, of Emory University School of Medicine in Atlanta, and colleagues reported results from an observational study that examined dabigatran (Pradaxa, Boehringer Ingleheim) adherence among patients with atrial fibrillation treated through the Veterans Health Administration system. They looked at variation in patient adherence, variation in practice at the site level and the association between site-level practices and patient adherence.

Medication adherence is especially critical with novel oral anticoagulants (NOACs) such as dabigatran. These drugs can be prescribed as an alternative to warfarin in atrial fibrillation patients at risk of stroke. Unlike warfarin, they don’t require blood monitoring to assess anticoagulation. Patients who skip doses or stop taking their medication increase their risk of stroke.

“For every 10% decrease in PDC [proportion of days covered], the hazard for all-cause mortality and stroke increased 13%,” Shore et al wrote.

They reviewed data from 4,863 patients who were prescribed dabigatran between 2010 and 2012 at 41 sites. The proportion of patients considered adherent ranged from 42 percent to 93 percent. They defined adherence as a PDC of at least 80 percent.

Almost all of the 41 sites in the study sites reported that pharmacists reviewed indications and contraindications, but only 24 percent looked at adherence to warfarin or other medications as criteria for patient selection. Previous nonadherence can raise a red flag; if these patients weren’t adherent during routine warfarin monitoring, then they may not be with a NOAC, either.

Among other site-level practices, 73 percent responded that they provided mandatory education led by a pharmacist before starting dabigatran treatment; 68.3 percent monitored patients for adherence and adverse events; 31.7 percent made the initiating pharmacist responsible for monitoring.

Sites that appropriately selected patients also had a higher proportion of adherent patients (75 percent vs. 69 percent), patient education (76 percent vs. 66 percent) and maintained monitoring (77 percent vs. 65 percent). After adjustments, the association between education and adherence was not statistically significant but patient selection and patient monitoring were associated with better adherence.

“These findings suggest that site-level practices provide modifiable targets to improve patient adherence to dabigatran as opposed to patient characteristics that frequently cannot be modified,” they wrote.

The use of NOACs has picked up steam in the U.S., with four options to warfarin now FDA approved. Warfarin is no longer the dominant anticoagulation treatment in the U.S. Given these patterns, Shore et al suggested it was time for randomized clinical trials to evaluate pharmacist-led and other strategies to improve adherence to NOACs.