Understanding and Improving Anticoagulation Dosing for Patients With Atrial Fibrillation

The pharmacy claims dataset will be used to obtain records of patient prescription fills, and the characteristics of those patients filling the prescriptions. The index event for each patient will be defined by when the second NVAF claim was filed. The dose will be initially determined from the index prescription. Of those patients prescribed a DOAC, the 12-month DOAC discontinuation rates will be examined. DOAC discontinuation will be defined as a gap in fill ≥30 days following the run-out date of the last observed claim for the index therapy. Twelve-month DOAC discontinuation will be stratified according to whether the patient received a dose reduction following labeled criteria, a dose reduction inconsistent with labeled criteria, or were prescribed the full dose, per labeled criteria.

The pharmacy claims dataset will be used to obtain records of patient prescription fills, and the characteristics of those patients filling the prescriptions. The index event for each patient will be defined by when the second NVAF claim was filed. The dose will be initially determined from the index prescription. Of those patients prescribed a DOAC, medication adherence rates will be examined. DOAC adherence, defined as the proportion of days covered ≥80%, is calculated by the number of days any anticoagulant is available divided by the number of days in the follow-up period. Twelve-month adherence rates will be stratified according to whether the patient received a dose reduction following labeled criteria, a dose reduction inconsistent with labeled criteria, or were prescribed the full dose, per labeled criteria.

Providers who contributed at least 25 NVAF patients on DOACs to the pharmacy claims dataset will be grouped into tertiles based on the frequency of under-dosing: high, intermediate, and low. We will examine the association of provider factors with the likelihood of under-dosing.