Factors That Affect Time to Switch From Warfarin to a Direct Oral Anticoagulant After Change in the Reimbursement Criteria in Patients With Atrial Fibrillation

Abstract

Background: Anticoagulation therapy is recommended for stroke prevention in high-risk patients with atrial fibrillation (AF). This study aimed to estimate the time to switch from warfarin to a direct oral anticoagulant (DOAC) and identify the factors associated with it. Methods: By using claims data, we studied 7111 warfarin-using patients with nonvalvular AF who were aged ≥65 years. The Kaplan-Meier analysis was performed to estimate the time to switch from warfarin to a DOAC, and Cox proportional hazard regression analysis was used to estimate the influencing factors. Results: Approximately one-third of the patients (2403, 33.8%) switched from warfarin to a DOAC during the study period. Female sex, aged between 75 and 79 years, having a Medical Aid or Patriots and Veterans Insurance, hypertension, and history of prior stroke, and transient ischemic attack or thromboembolism (prior stroke/TIA/TE) were associated with a significantly shorter time to switch. The odds of switching to a DOAC were increased by approximately 1.2-fold in the women and 1.4-fold in the patients with prior stroke/TIA/TE. Conclusions: Approximately one-third of the warfarin-using patients switched from warfarin to a DOAC within 6 months after the change in the DOAC reimbursement criteria. In the Cox proportional hazard regression analysis, the factors that affected anticoagulant switching from warfarin to a DOAC were female sex and history of prior stroke/TIA/TE.

Switching of oral anticoagulants in patients with nonvalvular atrial fibrillation: A narrative review

“…The majority of the studies were conducted in the United States (n = 10), 27,34,35,38,45,46,53,59,62,69 Nordic countries (n = 8; five, two and one from Denmark, Sweden and Norway, respectively) 33,44,47,48,50–52,63 and the UK (n = 5), 43,54,60,61,66 whereas three studies were multinational 32,37,56 . Claim databases and medical records were the principal type of data sources in most studies (n = 19) 27,33–36,38,40,42,45,51,53,57–59,64,66–69 . Primary care data, with or without linking to other data sources, were used in five studies; of these, four were conducted in the UK 43,54,60,61 and one in France 39 .…”

“…Fifteen studies reported the switching rate of DOACs as a class, with or without individual drug‐level switching 32,36,41,42,47,48,51–55,61,64–66 . Of the studies that assessed the switching rate, 14 studies were exclusively conducted among DOAC users, 33–35,38,41,47,48,51,53,55,59,61,64,66 five studies were in VKA users 44,46,49,57,62 and 13 studies were among users of both DOACs and VKAs 32,36,39,42,43,45,50,52,54,58,60,63,65 . The remaining four studies were focused on a single DOAC (two for dabigatran, 37,56 and one each for rivaroxaban 40 and apixaban 27 ).…”

“…Hypertension was the most common comorbidity reported by the studies (43.5‐97.3%) 45,52 . The majority of studies included patients who were newly commenced an OAC 27,32,34,35,37–39,42–45,49–60,62,63 (Appendix 3).…”

“…Switching rates in VKA users ranged from 2.7% to 33.8% 54,57 within a year of follow‐up. With the same duration of follow‐up, the rates for DOACs combined, apixaban, dabigatran and rivaroxaban users were 4.9‐14.9%, 48,61 2.8‐8.6%, 61,63 8.8‐21.0% 61,63 and 4.9‐15.0%, 40,61 respectively.…”

“…The highest rate for apixaban was 14% 27 during a mean follow‐up of 17.6 months, with 27.9% 33 and 21.3% 33 for dabigatran and rivaroxaban at median follow‐up times of 12.1 and 14.2 months, respectively. Except for patients prescribed apixaban, the highest switching rates were observed in studies that included patients who started on therapy between 2010 and 2015 33,48,57 . The peak apixaban switching rate occurred between 2013 and 2017 27 …”