Adherence to a Novel Oral Anticoagulant Among Patients with Atrial Fibrillation

Prescribing patterns in patients with chronic obstructive pulmonary disease and atrial fibrillation

Patients with chronic obstructive pulmonary disease (COPD) had higher risk of atrial fibrillation (AF). The treatment of AF includes medicines to control heart rate and reduce the risk of stroke, and procedures such as cardioversion to restore normal heart rhythm. To reduce the stroke, patients with AF may prescribe some type of antithrombotic medication (such as warfarin, one of the new non-vitamin K antagonist oral anticoagulants [NOACs] - dabigitran, apixaban, rivoraxaban, or edoxaban) or maybe aspirin. The aim of our study was to exam the prescription pattern in patients with COPD and AF. We selected COPD population in Taiwan older than 40 years and less than 90 years old with an COPD diagnosis at least two outpatient claims or at least one inpatient claim coded and also need at least one prescription of bronchodilators. We followed this COPD cohort until they have AF and their prescription pattern. We included 267,740 patients with COPD who meet the inclusion and exclusion criteria and 6,582 patients concomitant with COPD and AF. The mean age was 75 years, and about 77% of the patients were older than 70 years. Three-fourths of patients with COPD were male. The common comorbidities were hypertension (17.58%), diabetes (7.47%), ischemic heart disease (4.66%), and dyslipidemia (3.68%). we found that most patients received aspirin which accounting for 31%, followed by coumadin (8.22%) and clopidogrel. Prescribing NOAC within 30 days after AF diagnosis was low in patients with COPD and the percentage of NOAC usage was also lower than warfarin.

Prospective evaluation of the effect of smartphone electrocardiogram usage on anticoagulant medication compliance

PURPOSE

Compliance with anticoagulation treatment for atrial fibrillation is highly variable. Smartphone electrocardiograms that allow patients to have greater insight into their arrhythmia burden may improve anticoagulant compliance.

METHODS

Patients were enrolled if they had atrial fibrillation with a CHA₂DS₂-VASc score of 2 or more, were eligible for anticoagulation and had a smartphone. Participants were randomly assigned to receive a smartphone electrocardiogram (AliveCor Kardia) to record their electrocardiograms 5 times/week or to the control group. All patients received 6 months of anticoagulant (apixaban) dispensed as 1-month pre-loaded pill boxes.

RESULTS

A total of 100 patients were enrolled from July 2017 to August 2019, but 5 patients in the monitor arm and 1 in the control arm withdrew prematurely. The monitor and control groups did not differ in age, gender, CHA₂DS₂-VASc score, or comorbidities. Median medication compliance was 99.7%, with nonsignificantly greater compliance in the monitor group (100%) than in the control group (99.7%) (p-value = 0.247). There was also no significant difference between missing any dose and use/nonuse of the smartphone monitor (48.9% vs. 55.1%; p-value = 0.692). Mean monitor compliance was 86.8% ± 14.0% with an average of 4.34 recorded electrocardiograms per week. Monitor group patients with perfect medication compliance had significantly higher monitor compliance than those patients who missed doses (median 95.3% vs 86.7%; p-value = 0.02).

CONCLUSIONS

In a study population with higher-than-expected medication compliance, the use of smartphone electrocardiogram did not demonstrate an improvement in medication compliance as compared to usual care. Greater monitor compliance was associated with greater medication compliance.

CLINICAL TRIAL REGISTRATION

BOAT-OAR ClinicalTrials.gov number, NCT03515083.

Factors associated with primary nonadherence to newly initiated direct oral anticoagulants in patients with nonvalvular atrial fibrillation

BACKGROUND: Direct oral anticoagulants (DOACs) are widely used for the prevention of stroke in nonvalvular atrial fibrillation (NVAF); however, real-world primary nonadherence (failing to collect the first prescription) has been measured in very few studies. OBJECTIVE: To report primary nonadherence in NVAF patients who are newly prescribed DOACs and identify associated factors. METHODS: This observational retrospective cohort study used a large primary care database in Catalonia. Patients with NVAF who were newly prescribed a DOAC between January 2009 and December 2015 were identified, and primary nonadherence was measured by comparing prescribing records to pharmacy claims data. Multivariable logistic regression was used to determine associated factors. RESULTS: A total of 12,257 patients met the inclusion and exclusion criteria; of these, 1,276 (10.4%) were primary nonadherent. Primary nonadherence was found to be 12.8% for apixaban, 8.6% for dabigatran, and 10.8% for rivaroxaban. Multivariable logistic regression indicated higher odds of primary nonadherence with apixaban and rivaroxaban compared to dabigatran (apixaban: OR = 1.61, 95% CI = 1.39-1.87; rivaroxaban: OR = 1.28, 95% CI = 1.11-1.47). Patients aged at least 80 years showed lower odds of primary nonadherence compared to those aged less than 65 years (OR = 0.78, 95% CI = 0.66-0.93). A diagnosis of chronic kidney disease was associated with primary nonadherence (OR = 1.27, 95% CI = 1.08-1.50). Whereas, diabetes (OR = 0.85, 95% CI = 0.74-0.97), hypertension (OR = 0.79, 95% CI = 0.70-0.91), and stroke/transient ischemic attack (OR = 0.70, 95% C I =0.59-0.82) were inversely associated with primary nonadherence. CONCLUSIONS: Overall, 10.4% of patients prescribed DOACs were primary nonadherent, failing to collect the first prescription. The percentage could have serious implications for patient outcomes and the real-world cost-effectiveness of prescribing DOACs in NVAF. Rates of primary nonadherence and associated factors may provide useful information for the design and evaluation of adherence interventions. DISCLOSURES: No outside funding was received for this study. The data for this study came from the European Medicines Agency PE-PV project (Grant/Award Number EMA/2015/27/PH). The authors have nothing to disclose. A preliminary version of this work was presented at the European Drug Utilisation Research Group (EuroDURG) Conference, Szeged, Hungary, March 5, 2020.

Electronic monitoring of adherence to once-daily and twice-daily direct oral anticoagulants in patients with atrial fibrillation: Baseline data from the SMAAP-AF trial

BACKGROUND

Nonadherence diminishes the efficacy of direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation (NVAF). This report presents the baseline survey results regarding medication adherence among NVAF patients who were treated with once-daily edoxaban or twice-daily apixaban from a randomized control trial of the effect of an educational intervention on DOAC adherence.

METHODS

We prospectively studied 301 NVAF patients who were treated with edoxaban (n = 175) or apixaban (n = 126) during the 12-week observation period. Adherence was measured with an electronic monitoring system and is expressed as the percentage of days with the correct doses in the measurement period (days). Adherence to DOAC therapy was defined based on the standard threshold (≥80%) or a strict threshold (≥90%).

RESULTS

Of the 301 patients, 33 had incomplete data or protocol deviations, leaving 268 patients (edoxaban 158 and apixaban 110) for the per-protocol baseline analysis. There was no difference in adherence (threshold ≥80%) between the groups (edoxaban 95% vs apixaban 91%, P = .2), but there was a lower proportion of patients with strict adherence (threshold ≥90%) among apixaban users than among edoxaban users (edoxaban 87% vs apixaban 76%, P = .02). Multivariate analysis showed a negative relationship between apixaban use and an adherence rate ≥90% (odds ratio 0.49, 95% confidence interval [CI]: 0.25-0.94).

CONCLUSIONS

Our study showed that the proportion of DOAC users with adherence (≥80%) did not differ between the groups, but the proportion of patients with strict adherence (≥90%) was lower among those using apixaban than among those using edoxaban.

Methodological considerations for investigating oral anticoagulation persistence in atrial fibrillation

Aims 

Reports of long-term oral anticoagulant (OAC) therapy for atrial fibrillation (AF) reveal highly variable, and generally suboptimal estimates of medication persistence. The objective of this review is to summarize current literature and highlight important methodological considerations for interpreting persistence research and designing studies of persistence on OAC treatment.

Methods and results 

We summarize differences in study methodology, setting, timing, treatment, and other factors associated with reports of better or worse persistence. For example, prospective compared with retrospective study designs are associated with higher reported persistence. Similarly, patient factors such as permanent AF or high stroke risk, and treatment with non-vitamin K oral antagonists relative to vitamin K antagonists are associated with higher persistence. Persistence has also been reported to be higher in Europe compared with North America and higher when the treating physician is a general practitioner compared with a specialist. We propose a framework for assessing and designing persistence studies. This framework includes aspects of patient selection, reliability and validity of measures, persistence definitions, clinical utility of measurements, follow-up periods, and analytic approaches.

Conclusions 

Differences in study design, patient selection, treatments, and factors such as the countries/regions where studies are conducted or the type of treating physician may help explain the variability in OAC persistence estimates. A framework is proposed to assess persistence studies. This may have utility to compare and interpret published studies as well as for planning of future studies.

Adherence to oral anticoagulants among patients with atrial fibrillation: a systematic review and meta-analysis of observational studies

INTRODUCTION

Medications cannot exert their effect if not taken as prescribed by patients. Our objective was to summarise the observational evidence on adherence to oral anticoagulants (OACs) among patients with atrial fibrillation (AF).

METHODS

In March 2019, we systematically searched PubMed/Medline, Embase, CINAHL and PsycINFO (from inception) for observational studies measuring adherence, its determinants and impacts in patients with AF. Mean adherence measures and corresponding proportions of adherent patients were pooled using random effects models. Factors shown to be independently associated with adherence were extracted as well as the clinical and economic outcomes of adherence.

RESULTS

We included 30 studies. Pooled mean adherence scores of over half a million patients with AF 6 months and 1 year after therapy initiation were 77 (95% CI: 74-79) and 74 (68-79) out of 100, respectively. Drug-specific pooled mean adherence score at 6 months and 1 year were as follows: rivaroxaban: 78 (73-84) and 77 (69-86); apixaban: 77 (75-79) and 82 (74-89); dabigatran: 74 (69-79) and 75 (68-82), respectively. There was inadequate information on warfarin for inclusion in meta-analysis.Factors associated with increased adherence included: older age, higher stroke risk, once-daily regimen, history of hypertension, diabetes or stroke, concomitant cardiovascular medications, living in rural areas and being an experienced OAC user. Non-adherent patients were more likely to experience stroke and death, and incurred higher medical costs compared with patients with poor adherence.

CONCLUSIONS

Our findings show that up to 30% of patients with AF are non-adherent, suggesting an important therapeutic challenge in this patient population.

Real-World Adherence and Persistence to Direct Oral Anticoagulants in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND

Stroke reduction with direct oral anticoagulants (DOACs) in atrial fibrillation (AF) is dependent on adherence and persistence in the real-world setting. Individual study estimates of DOAC adherence/persistence rates have been discordant. Our aims were to characterize real-world observational evidence for DOAC adherence/persistence and evaluate associated clinical outcomes in patients with AF.

METHODS AND RESULTS

PubMed, EMBASE, and CINAHL were searched from inception to June 2018. Observational studies that reported real-world DOAC adherence/persistence in patients with AF were included. Study quality was assessed using the Newcastle-Ottawa Scale. Meta-analyses for pooled estimates were performed using DerSimonian and Laird random-effects models. Outcomes included DOAC mean proportion of days covered or medication possession ratio, proportion of good adherence (proportion of days covered/medication possession ratio ≥80%), persistence, DOAC versus vitamin K antagonists persistence, and clinical outcomes associated with nonadherence/nonpersistence. Forty-eight observational studies with 594 784 unique patients with AF (59% male; mean age 71 years) were included. The overall pooled mean proportion of days covered/medication possession ratio was 77% (95% CI, 75%-80%), proportion of patients with good adherence was 66% (95% CI, 63%-70%), and proportion persistent was 69% (95% CI, 65%-72%). The pooled proportion of patients with good adherence was 71% (95% CI, 64%-78%) for apixaban, 60% (95% CI, 52%-68%) for dabigatran, and 70% (95% CI, 64%-75%) for rivaroxaban. Similar patterns were found for pooled persistence by agent. The pooled persistence was higher with DOACs than vitamin K antagonists (odds ratio, 1.44 [95% CI, 1.12-.86]). DOAC nonadherence was associated with an increased risk of stroke (hazard ratio, 1.39 [95% CI, 1.06-1.81]).

CONCLUSIONS

Suboptimal adherence and persistence to DOACs was common in patients with AF, with 1 in 3 patients adhering to their DOAC <80% of the time, which was associated with poor clinical outcomes in nonadherent patients. Although it is convenient that DOACs do not require laboratory monitoring, greater effort in monitoring for and interventions to prevent nonadherence may be necessary to optimize stroke prevention. Increased clinician awareness of DOAC nonadherence may help identify at-risk patients.

Persistence of oral anticoagulant treatment for atrial fibrillation in the Netherlands: A surveillance study

BACKGROUND

In contrast to vitamin K antagonists (VKA), direct oral anticoagulants (DOAC's) are not strictly monitored and dose titrated by anticoagulation clinics in the Netherlands. This may affect drug persistence of atrial fibrillation (AF) patients, whom often require lifelong treatment.

OBJECTIVES

To assess persistence of DOACs and of VKAs in patients with AF.

METHODS

Dispensing data from the Dutch Foundation of Pharmaceutical Statistics were used to monitor persistence of AF patients to DOAC from 1 January 2012-1 April 2016. In addition, we estimated the persistence of AF patients to VKA between 1 January 2004 and 1 January 2012 in data from the Anticoagulation Clinic Leiden. Non-persistence was defined as the cumulative incidence of patients who completely stopped DOAC, switched to another oral anticoagulant or stopped their VKA.

RESULTS

DOAC users (n = 77 333) were younger than VKA users (n = 10 079; 70 vs 73 years). Non-Persistence to DOAC (ie stopping with any oral anticoagulant) was 34% at 1 and 64% at 4 years, compared to 22% at one and 36% at 4 years for VKA. Approximately a Twenty-five percent of those who had stopped their initial DOAC switched to another anticoagulant (VKA or another DOAC). Multivariable analyses revealed that young age, female sex, no concomitant drug use and non-adherence were predictors for non-persistence of DOAC.

CONCLUSIONS

Persistence to DOAC was low and in line with other observational studies, and higher for VKA. Our results show a clear correlation between age <60 years and worse persistence, as well as with female and non-adherence to DOAC.

The treatment pattern and adherence to direct oral anticoagulants in patients with atrial fibrillation aged over 65

Objective

In this study, we aimed to assess the utilization pattern (potentially inappropriate dosing and concomitant use of contraindicated drugs) and adherence to direct oral anticoagulants (DOACs), including apixaban, dabigatran, and rivaroxaban, in patients with atrial fibrillation (AF) unsuitable for warfarin.

Methods

We used nationally representative data, namely Health Insurance Review and Assessment Service-Aged Patient Sample 2014, that included medical and pharmacy claims of approximately 1 million patients aged 65 or older. We included patients who had at least one diagnosis of AF and at least one prescription of DOAC between January 1 and December 31, 2014. In 2014, DOACs were reimbursed only to patients with AF unsuitable for warfarin. Appropriate dosing and contraindicated drugs were determined according to the Summary of Product Characteristics for each DOAC. Multivariate logistic regression was performed to examine the factors contributing to the concomitant use of contraindicated drugs. To assess adherence, we calculated the medication possession ratio (MPR).

Results

The percentage of inappropriate dosing was 11.8% among 1,234 patients with AF; it was the highest in rivaroxaban users (16.8%). Contraindicated drugs were prescribed to 236 patients (19.1%). Clinics, smaller healthcare institutions, and outpatient visits were significantly related to contraindicated drug use. The mean MPRs were 0.95, 0.93, and 0.91 for apixaban, dabigatran, and rivaroxaban, respectively (P = 0.075).

Conclusions

Careful monitoring is warranted in patients with AF aged over 65 who were unsuitable for warfarin to reduce the incidence of inappropriate dosing and concomitant use of contraindicated drugs.

Real-world adherence for direct oral anticoagulants in a newly diagnosed atrial fibrillation cohort: does the dosing interval matter?

Background

Differences in adherence may represent drug properties (e.g. dosing interval) or patient experiences while on treatment. Adherence to direct oral anticoagulants (DOACs) in nonvalvular atrial fibrillation (NVAF) is important to maintain effectiveness over the course of treatment.

Methods

This was a retrospective cohort study using 2009–2015 Truven Health MarketScan Databases. New initiators of dabigatran, rivaroxaban, and apixaban with NVAF were identified. Twelve months of continuous enrollment before treatment was required to assess demographics and medical history. Proportion of days cover (PDC) was used to measure adherence at 3, 6, 9 and 12-month. Gaps in therapy and treatment switches were also evaluated. Logistic regression was used to compare high adherence (PDC ≥0.80).

Results

A total of 14,864 dabigatran, 16,005 rivaroxaban, and 8078 apixaban users were identified. Apixaban users had the highest adherence overall, with mean PDC at 3, 6, 9, and 12-months of 0.83, 0.76, 0.72, and 0.69, while dabigatran had the lowest adherence of 0.78, 0.67, 0.61, and 0.57. Adherence to DOACs increased with increased stroke risk scores. Adherence was also higher when first days supplied was > 30 days compared to 30 days and when filled via mail order pharmacies. Switching was highest among dabigatran users. Apixaban users were the most likely to have high adherence versus dabigatran (OR = 1.73, 95% CI = 1.60–1.88) and versus rivaroxaban (OR = 1.24, 95% CI = 1.14–1.34) at 12-months.

Conclusions

Apixaban users had the highest overall adherence despite twice-daily dosing versus once-daily dosing for rivaroxaban. These findings can be useful for formulary decision-making and when assessing treatment options.

Real-world adherence to oral anticoagulants in atrial fibrillation patients: a study protocol for a systematic review and meta-analysis

INTRODUCTION

Atrial fibrillation (AF) is one of the leading causes of cerebrovascular mortality and morbidity. Oral anticoagulants (OACs) have been shown to reduce the incidence of cardioembolic stroke in patients with AF, adherence to treatment being an essential element for their effectiveness. Since the release of the first non-vitamin K antagonist oral anticoagulant, several observational studies have been carried out to estimate OAC adherence in the real world using pharmacy claim databases or AF registers. This systematic review aims to describe secondary adherence to OACs, to compare adherence between OACs and to analyse potential biases in OAC secondary adherence studies using databases.

METHODS AND ANALYSIS

We searched on PubMed, SCOPUS and Web of Science databases (completed in 26 September 2018) to identify longitudinal observational studies reporting days' supply adherence measures with OAC in patients with AF from refill databases or AF registers. The main study endpoint will be the percentage of patients exceeding the 80% threshold in proportion of days covered or the medication possession ratio. Two reviewers will independently screen potential studies and will extract data in a structured format. A random-effects meta-analysis will be carried out to pool study estimates. The risk of bias will be assessed using the Newcastle-Ottawa Scale for observational studies and we will also assess some study characteristics that could affect days' supply adherence estimates.

ETHICS AND DISSEMINATION

This systematic review using published aggregated data does not require ethics approval according to Spanish law and international regulations. The final results will be published in a peer-review journal and different social stakeholders, non-academic audiences and patients will be incorporated into the diffusion activities.

PROSPERO REGISTRATION NUMBER

CRD42018095646.

Secondary adherence to non-vitamin-K antagonist oral anticoagulants in patients with atrial fibrillation in Sweden and the Netherlands

OBJECTIVE

There is limited evidence on patients' adherence and the impact of the prescribed dosing regimen in non-vitamin-K oral anticoagulants (NOACs). We aimed to assess secondary adherence to NOACs and to determine the impact of the dosing regimen in patients with atrial fibrillation.

METHODS

Patients using a NOAC between 2009 and 2013 were identified from the nation-wide Swedish Prescribed Drug Register and the Dutch regional IADB.nl database. Patients using a consistent dosage for at least 180 consecutive days were included. Adherence was calculated using the medication possession ratio (MPR) and adjusted for overlapping dates. Adherence was defined as a MPR ≥0.8. Sensitivity analyses were performed using a MPR ≥0.9. Logistic regression was performed to compare secondary adherence and to explore the influence of the dosing regimen.

RESULTS

A total of 5254 Swedish and 430 Dutch NOAC users were included. The mean MPR was 96.0% (SD 7.8%) in Sweden and 95.1% (SD 10.1%) in the Netherlands. Multivariable logistic regression analysis showed that a twice daily regimen had a lower likelihood of being secondary adherent compared to a once daily regimen in Sweden (odds ratio [OR] 0.21 [95% CI 0.12-0.35]).

LIMITATIONS

The influence of selection bias introduced by the inclusion criterion of ≥2 dispensations covering at least 180 days could not be excluded.

CONCLUSIONS

This study demonstrated that secondary adherence was high in this specific setting among patients with at least two initial dispensations of a NOAC covering a minimum of 180 days. The use of NOACs in a once daily regimen showed higher adherence compared to a twice daily regimen.

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

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.

DISCLOSURES

This project was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through grant number UL1TR000117. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The authors have nothing to disclose. Study concept and design were contributed by Brown and Shewale. Brown and Talbert collected the data, and data analysis was performed primarily by Brown, along with Shewale and Talbert. The manuscript was written primarily by Brown, along with Shewale, and revised by all the authors.

Once- versus twice-daily direct oral anticoagulants in non-valvular atrial fibrillation

INTRODUCTION

Direct oral anticoagulants (DOACs) have emerged as alternatives to vitamin K antagonists for the prevention of stroke in patients with non-valvular atrial fibrillation (NVAF). Four DOACs: dabigatran, rivaroxaban, apixaban and edoxaban, are currently available. In the absence of head-to-head clinical comparisons of DOACs, dosing regimen may influence drug choice. Areas covered: Edoxaban and rivaroxaban are administered once daily, dabigatran and apixaban twice daily. The selection of these dosage regimens is largely based on studies for the prevention or treatment of venous thromboembolism or acute coronary syndrome. Edoxaban is the only DOAC in which once and twice-daily regimens were compared in patients with NVAF; bleeding rates were higher in the twice-daily groups. Once-daily versus twice-daily regimens have a number of practical implications. Missing a once-daily dose would have a greater impact on anticoagulation. Some real world and retrospective studies found that a once-daily dosing regimen leads to better adherence and persistence to therapy, an important consideration for maintaining optimum anticoagulation. However, other studies have not found increased adherence among once daily regimens. Expert opinion: Prescription of DOACs should be tailored to the individual patient and dosing regimen is only one of the variables that should be taken into account.

Adherence with direct oral anticoagulants in nonvalvular atrial fibrillation new users and associated factors: a French nationwide cohort study

Purpose

Direct oral anticoagulants (DOACs) have been promoted in patients with nonvalvular atrial fibrillation (nv‐AF) as a more convenient alternative to vitamin K antagonists. We estimated 1‐year dabigatran and rivaroxaban adherence rates in nv‐AF patients and assessed associations between baseline patient characteristics and nonadherence.

Methods

This cohort study included OAC‐naive nv‐AF patients with no contraindications to OAC, who initiated dabigatran and rivaroxaban, using nationwide data from French national health care databases. One‐year adherence was defined by the proportion of days covered of 80% or more over a fixed 1‐year period after treatment initiation. Associations between nonadherence and baseline patient characteristics were assessed using multivariate logistic regression models.

Results

The population was composed of 11 141 dabigatran (women: 48%; mean age: 74 ± 10.7 y; ≥80 y: 34.9%) and 11 126 rivaroxaban (46.5%; 74 ± 10.9 y; 34.8%) new users. One‐year adherence was 53.3% in dabigatran‐treated and 59.9% in rivaroxaban‐treated patients, consistent with numerous subgroup analyses. A switch to vitamin K antagonist was observed in 14.5% of dabigatran and 11.7% of rivaroxaban patients; 10.2% and 5.9% of patients switched to another DOAC, respectively; and 4.3% of patients died in the 2 cohorts. In patients who did not die or switch during the follow‐up, 1‐year adherence was 69.6% in dabigatran‐treated and 72.3% in rivaroxaban‐treated patients. Having concomitant ischemic heart diseases was associated with an increased risk of nonadherence in the 2 cohorts.

Conclusion

In this real‐life study, 1‐year adherence to DOAC is poor in nv‐AF new users. Despite the introduction of DOAC, adherence to OACs may remain a significant challenge in AF patients.

Adherence to Rivaroxaban, Dabigatran, and Apixaban for Stroke Prevention in Incident, Treatment-Naïve Nonvalvular Atrial Fibrillation

BACKGROUND

Non-vitamin K antagonist oral anticoagulants (NOACs) are widely used for prevention of stroke secondary to nonvalvular atrial fibrillation (NVAF). Increased use of NOACs is partially a result of simplified regimens compared with warfarin, which has been associated with poor adherence and persistence to therapy. Few studies have assessed adherence to NOACs, especially using contemporary data now that multiple NOACs are available.

OBJECTIVE

To evaluate adherence to NOACs in a cohort of newly diagnosed NVAF patients who are commercially insured.

METHODS

Incident, treatment-naïve NVAF patients were identified in 2013 from a large claims database. Patients were included who initiated rivaroxaban, dabigatran, or apixaban within 30 days after diagnosis. Subjects were required to have 12 months of pre-index information to assess demographic and clinical characteristics (comorbidities, CHA₂ DS₂-VASc, and HAS-BLED scores). Adherence to the index medication and adherence to any oral anticoagulant was assessed using 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 (PDC ≥ 0.80).

RESULTS

A total of 3,455 rivaroxaban, 1,264 dabigatran, and 504 apixaban users were included with no major clinical or demographic differences between groups. At 3, 6, and 9 months of follow-up, dabigatran had lower adherence (PDC = 0.77, 0.67, and 0.62) compared with rivaroxaban (PDC = 0.84, 0.75, and 0.70; P < 0.001) and apixaban (PDC = 0.82, 0.75, and 0.71; P < 0.001), as well as nearly twice the number of switches to either other anticoagulants or antiplatelet therapy. At 9 months, 55.0% of rivaroxaban initiators had PDC ≥ 0.80, which was comparable with 56.8% for apixaban and significantly greater than 46.7% for dabigatran (P < 0.001). Adherence was higher overall as stroke risk increased and showed dabigatran had consistently lower adherence compared with the other NOACs. Overall adherence to any oral anticoagulants, allowing for switches to another NOAC or warfarin, was not dependent on the index medication (9-month PDC = 0.74, 0.71, and 0.74 for rivaroxaban, dabigatran, and apixaban initiators). Adjusted analyses showed that increasing age and comorbid hypertension and diabetes were associated with higher adherence. Compared with rivaroxaban, dabigatran initiators had nearly 30% lower odds of being adherent to their index medication, and no differences were observed between apixaban and rivaroxaban. At 9 months, there were no differences between NOACs for overall adherence to oral anticoagulants.

CONCLUSIONS

In this real-world analysis of adherence to NOACs, rivaroxaban and apixaban had favorable profiles compared with dabigatran, and rivaroxaban appeared to have higher overall adherence among the NOACs. Clinicians and managed care organizations should consider the implications of lower adherence on clinical outcomes as well as quality assessment.

DISCLOSURES

The project described was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through grant number UL1TR000117. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Brown reports receiving a training fellowship from Human and Pfizer. Study concept and design were contributed by Brown and Shewale. Talbert took the lead in data collection, along with Brown, and data interpretation was primarily performed by Brown, along with Shewale. The manuscript was written primarily by Brown, along with Shewale, and revised by all the authors.

Using Artificial Intelligence to Reduce the Risk of Nonadherence in Patients on Anticoagulation Therapy

BACKGROUND AND PURPOSE

This study evaluated the use of an artificial intelligence platform on mobile devices in measuring and increasing medication adherence in stroke patients on anticoagulation therapy. The introduction of direct oral anticoagulants, while reducing the need for monitoring, have also placed pressure on patients to self-manage. Suboptimal adherence goes undetected as routine laboratory tests are not reliable indicators of adherence, placing patients at increased risk of stroke and bleeding.

METHODS

A randomized, parallel-group, 12-week study was conducted in adults (n=28) with recently diagnosed ischemic stroke receiving any anticoagulation. Patients were randomized to daily monitoring by the artificial intelligence platform (intervention) or to no daily monitoring (control). The artificial intelligence application visually identified the patient, the medication, and the confirmed ingestion. Adherence was measured by pill counts and plasma sampling in both groups.

RESULTS

For all patients (n=28), mean (SD) age was 57 years (13.2 years) and 53.6% were women. Mean (SD) cumulative adherence based on the artificial intelligence platform was 90.5% (7.5%). Plasma drug concentration levels indicated that adherence was 100% (15 of 15) and 50% (6 of 12) in the intervention and control groups, respectively.

CONCLUSIONS

Patients, some with little experience using a smartphone, successfully used the technology and demonstrated a 50% improvement in adherence based on plasma drug concentration levels. For patients receiving direct oral anticoagulants, absolute improvement increased to 67%. Real-time monitoring has the potential to increase adherence and change behavior, particularly in patients on direct oral anticoagulant therapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02599259.

A Summary of the Literature Evaluating Adherence and Persistence with Oral Anticoagulants in Atrial Fibrillation

Atrial fibrillation (AF) is a growing public health concern and remains an independent risk factor for ischemic stroke. Warfarin, a commonly used oral anticoagulant, is associated with a 60-70 % relative reduction in stroke risk and a reduction in mortality of 26 %. However, warfarin has several limitations, including a narrow therapeutic window, variable dose response, multiple interactions with other drugs and concurrent illnesses, and the need for frequent laboratory monitoring. In recent years, the direct acting oral anticoagulants (DOACs), including dabigatran, rivaroxaban, apixaban and edoxaban, have been developed to overcome the limitations of warfarin therapy. These treatment strategies are either comparable or superior to warfarin in stroke prevention in AF. Despite the documented effectiveness of oral anticoagulants in AF, patients may not derive optimal benefit if they fail to adhere or fail to continue with their medication. This may lead to treatment failure, increased hospitalization and mortality. This review summarizes the literature regarding adherence and persistence (or discontinuation) rates with oral anticoagulants in the management of AF; the impact of non-adherence and non-persistence on treatment outcomes; and the effectiveness of strategies to improve adherence and persistence with oral anticoagulant therapy.