Adherence to Rivaroxaban, Dabigatran, and Apixaban for Stroke Prevention for Newly Diagnosed and Treatment-Naive Atrial Fibrillation Patients: An Update Using 2013-2014 Data

Abstract

BACKGROUND Few studies have assessed adherence to non-vitamin K antagonist oral anticoagulants (NOACs), especially using contemporary data now that multiple NOACs are available. OBJECTIVE To compare adherence and treatment patterns among NOACs for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). METHODS Incident and treatment-naive NVAF patients were identified during 2013–2014 from a large claims database in this retrospective cohort study. Patients were included who initiated rivaroxaban, dabigatran, or apixaban within 30 days after diagnosis. Adherence to the index medication and adherence to any oral anticoagulant was assessed using the proportion of days covered (PDC) at 3, 6, and 9 months. The number of switches and gaps in therapy were also evaluated. Analyses were stratified by stroke risk scores, and a logistic regression model was used to control for factors that may predict high adherence. RESULTS Dabigatran had lower adherence (PDC = 0.76, 0.64, 0.57) compared with rivaroxaban (PDC = 0.83, 0.73, 0.66; P < 0.001) and apixaban (PDC = 0.82, 0.72, 0.66; P < 0.001) at 3, 6, and 9 months of follow-up and twice the number of switches to either other anticoagulants or antiplatelet therapy. Adherence was higher overall as stroke risk increased, and dabigatran had consistently lower adherence compared with the other NOACs. Multivariable logistic regression predicting PDC ≥ 0.80 showed rivaroxaban users with higher odds of high adherence compared with dabigatran or rivaroxaban across all time periods. Adjusted analyses showed that increasing age and comorbid hypertension and diabetes were associated with higher adherence. CONCLUSIONS In this real-world analysis of adherence to NOACs, rivaroxaban and apixaban had favorable unadjusted adherence profiles compared with dabigatran, while rivaroxaban users had higher odds of high adherence (PDC ≥ 0.80) among the NOACs in adjusted analyses. Clinicians and managed care organizations should consider the implications of lower adherence on clinical outcomes and quality assessment.

Association of Oral Anticoagulants and Verapamil or Diltiazem With Adverse Bleeding Events in Patients With Nonvalvular Atrial Fibrillation and Normal Kidney Function

“…Our exposure definition required continuous adherence with a small gap window (7-day) to ensure exposure. 33,34 Likewise, the claims database would not include information on when patients acquired prescriptions not paid for by their insurance coverage, such as over-the-counter or sample medications, [35][36][37] but this information is not expected to be imbalanced between treatment groups and would likely not affect the study results. Our results were consistent in direction and magnitude to several sensitivity analyses including use of standardized mortality ratio weighting in place of IPTW, use of a 15-day gap censor criterion, outcome measurement using all primary and secondary diagnoses, and separating verapamil and diltiazem.…”

Dabigatran Persistence and Outcomes Following Discontinuation in Atrial Fibrillation Patients from the GLORIA-AF Registry

“…Overall 2-year dabigatran persistence was 70.9% (95% confidence interval [CI] 69.6 to 72.2). Persistence probability was lower in the first 6 ). Of 1,305 patients (26.9%) who discontinued dabigatran, adverse events were reported as the reason for discontinuation in 457 (35.0%).…”

“…1 Although current guidelines recommend long-term oral anticoagulation (OAC) for stroke prevention in AF patients with at least 1 additional stroke risk factor, 2 high rates of OAC discontinuation have posed a barrier to achieving optimal outcomes. Discontinuation has been especially noteworthy in the era before the availability of nonvitamin K antagonist OACs (NOAC) with 1-year discontinuation rates exceeding 50% 3−5 ; and investigations examining persistence or adherence have primarily been based on claims databases, 6,7 national health registers, 8−11 or commercial databases. 12 Although some evidence indicates discontinuation rates may be lower with NOACs versus vitamin K antagonists, 5,7,13 periods of risk and reasons for NOAC discontinuation remain poorly understood.…”

Preliminary Observations on the Antihypertension Action of Dabigatran Etexilate in Patients With Nonvalvular Atrial Fibrillation: A Prospective Multicenter Single-Arm Interventional Study

“…Although it was reported that adherence to dabigatran is poor in patients with NVAF [11], the mean aPTT showed sta- ble prolongation throughout the present study, suggesting that our patients showed good adherence. This finding supports the favorable adherence to dabigatran therapy and good safety profile revealed by a post-marketing survey in Japan [12].…”