Decentralized vs Centralized Pharmacist Treatment of Patients With Atrial Fibrillation Managed With Direct Oral Anticoagulants

Limitations

This study had several potential limitations. First, MPR, a widely studied common tool for assessing adherence, has been criticized for often being imprecise when used with short study periods.¹² Another commonly used adherence measure is PDC rate, which has been reported in several large-scale studies of dabigatran therapy. The authors selected MPR for the present study because MPR calculation is more practical in the patient population and because MPR and PDC rate are predicted to yield similar results in assessments of adherence to a single medication.¹² It also should be noted that both MPR and PDC rate are surrogate markers for adherence and assume adherence based on the availability of medication to the patient. Assessing adherence in a retrospective study is a challenge, as more reliable adherence assessment--for example, with use of pill counts or blister packs--is not possible. This study's retrospective design was another potential limitation, as an active intervention was not used.

In addition, this study had a small sample, likely attributable to the addition of dabigatran to the VA national formulary just months before the start of the study period. Furthermore, this study was not powered to detect significant differences in safety or efficacy outcomes. Other potential study limitations included having national VA guidance regarding follow-up periods and dabigatran prescription quantity limits during both study periods. Also, there was some potential for pharmacist-initiated refills at follow-up visits, which could falsely increase MPR. Last, the study analyzed only 1 DOAC and not the entire class of medications.  

Conclusion

Centralizing DOAC management by clinical pharmacy specialists at a single VA facility helped maintain high rates of dabigatran adherence, above the national average, and low rates of adverse outcomes were maintained in both study groups. In addition, centralization of anticoagulation services improved access to care through an increase in primary care pharmacist visits without the addition of staff. Centralization of DOAC management by pharmacists is a viable option for maintaining high rates of adherence and low rates of adverse outcomes in facilities where the goal is to achieve clinical efficiency.