Adherence to rivaroxaban versus apixaban among patients with non-valvular atrial fibrillation: Analysis of overall population and subgroups of prior oral anticoagulant users

Association of Tumor Necrosis Factor Inhibitors with the Risk of Nontuberculous Mycobacterial Infection in Patients with Rheumatoid Arthritis: A Nationwide Cohort Study

Tumor necrosis factor inhibitors (TNFi) are proposed as a risk factor for nontuberculous mycobacteria (NTM) infection. Limited research investigates NTM infection risk in rheumatoid arthritis (RA) patients treated with TNFi compared to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), considering other concurrent or prior non-TNFi antirheumatic drugs. We aimed to evaluate the NTM infection risk associated with TNFi using a real-world database. Patients with RA treated with TNFi or csDMARDs between 2005 and 2016 were identified utilizing the Korean National Health Insurance Service database. To minimize potential bias, we aligned the initiation year of csDMARDs for both TNFi and csDMARD users and tracked them from their respective treatment start dates. The association of TNFi with NTM infection risk was estimated in a one-to-one matched cohort using a multivariable conditional Cox regression analysis. In the matched cohort (n = 4556), the incidence rates of NTM infection were 2.47 and 3.66 per 1000 person-year in TNFi and csDMARD users. Compared to csDMARDs, TNFi did not increase the risk of NTM infection (adjusted hazard ratio (aHR) 0.517 (95% confidence interval, 0.205-1.301)). The TNFi use in RA patients was not associated with an increased risk of NTM infection compared to csDMARDs. Nevertheless, monitoring during TNFi treatment is crucial.

Anticoagulant Treatment Adherence and Persistence in German Patients with Atrial Fibrillation

INTRODUCTION

Treatment adherence and persistence impact the effectiveness of edoxaban for the prevention of thromboembolism in patients with atrial fibrillation (AF). The objective of this analysis was to assess adherence and persistence of edoxaban vs. other non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (VKAs).

METHODS

Utilizing a German claims database, adults with AF with the first pharmacy claim identified for edoxaban, apixaban, dabigatran, rivaroxaban, or VKAs from January 2013 to December 2017 were included in a propensity score-matched analysis. The first pharmacy claim was the index claim. Adherence (i.e., proportion of days covered [PDC]) and persistence (proportion of patients who continued therapy) were compared between edoxaban and other therapies. Patients receiving once-daily (QD) vs. twice-daily (BID) NOAC were also analyzed.

RESULTS

Overall, 21,038 patients were included (1236 edoxaban, 6053 apixaban, 1306 dabigatran, 7013 rivaroxaban, and 5430 VKA). After matching, baseline characteristics were well balanced across cohorts. Adherence was significantly higher for edoxaban vs. apixaban, dabigatran, and VKAs (all P < 0.0001). Significantly more edoxaban patients continued therapy vs. rivaroxaban (P = 0.0153), dabigatran (P < 0.0001), and VKAs (P < 0.0001). Time to discontinuation was significantly longer for edoxaban vs. dabigatran, rivaroxaban, and VKAs (all P < 0.0001). More patients receiving NOACs QD had a PDC ≥ 0.8 compared with those receiving NOACs BID (65.3 vs. 49.6%, respectively; P < 0.05); persistence rates were comparable between QD and BID groups.

CONCLUSIONS

Patients with AF receiving edoxaban had significantly higher adherence and persistence compared with those receiving VKAs. This trend was also seen in NOAC QD regimens vs. NOAC BID regimens for adherence. These results provide insight into how adherence and persistence may contribute to the effectiveness of edoxaban for stroke prevention in patients with AF in Germany.

Use of anticoagulant drugs in patients with atrial fibrillation. Does adherence to therapy have a prognostic impact?

Anticoagulant therapy represents a pivotal element that strongly influences the thromboembolic risk of non-valvular atrial fibrillation (NVAF) subjects. The main purpose of this review was to identify issues and suggest strategies to improve the oral anticoagulants (OACs) treatment adherence, which is the most important predictor of NVAF outcome. Advantages, efficacy, and impact of these drugs on patients' prognosis were revealed in important clinical trials on large cohorts of patients and are often prescribed nowadays. A real-life data registry, the Global Anticoagulant Registry in the Field-Atrial Fibrillation (GARFIELD-AF) analyzed the profile and outcome of patients diagnosed with NVAF receiving oral antithrombotic treatment. The observations gathered in the registry were crucial for identifying relevant elements that clinicians must improve, such as adherence strategies and predisposing factors that correlated with stroke. Adherence to OACs in AF patients is essential from the viewpoint of clinical efficacy and safety. Major adverse events and negative outcome are correlated with a weak anticoagulation control caused by an ineffective treatment adherence strategy. Solving the issue of oral anticoagulation adherence is possible using new technologies, but future directions should be explored. Mobile phone applications centered on patients' needs, telemedicine programs that evaluate patients' evolution and detect adverse reactions or events, encouraging an adequate management of the event without interruption of OACs, represent perspectives with a major impact on treatment adherence.

Towards better reporting of the Proportion of Days Covered method in cardiovascular medication adherence: A scoping review and new tool TEN-SPIDERS

Although medication adherence is commonly measured in electronic datasets using the proportion of days covered (PDC), no standardized approach is used to calculate and report this measure. We conducted a scoping review to understand the approaches taken to calculate and report the PDC for cardiovascular medicines to develop improved guidance for researchers using this measure. After prespecifying methods in a registered protocol, we searched Ovid Medline, Embase, Scopus, CINAHL Plus and grey literature (1 July 2012 to 14 December 2020) for articles containing the terms “proportion of days covered” and “cardiovascular medicine”, or synonyms and subject headings. Of the 523 articles identified, 316 were reviewed in full and 76 were included (93% observational studies; 47% from the USA; 2 grey literature articles). In 45 articles (59%), the PDC was measured from the first dispensing/claim date. Good adherence was defined as 80% PDC in 61 articles, 56% of which contained a rationale for selecting this threshold. The following parameters, important for deriving the PDC, were often not reported/unclear: switching (53%), early refills (45%), in‐hospital supplies (45%), presupply (28%) and survival (7%). Of the 46 articles where dosing information was unavailable, 59% reported how doses were imputed. To improve the transparent and systematic reporting of the PDC, we propose the TEN‐SPIDERS tool, covering the following PDC parameters: Threshold, Eligibility criteria, Numerator and denominator, Survival, Presupply, In‐hospital supplies, Dosing, Early Refills, and Switching. Use of this tool will standardize reporting of the PDC to facilitate reliable comparisons of medication adherence estimates between studies.

Long-Term Medication Adherence Trajectories to Direct Oral Anticoagulants and Clinical Outcomes in Patients With Atrial Fibrillation

Background

Direct oral anticoagulants (DOACs) are widely used in patients with nonvalvular atrial fibrillation for stroke prevention. However, long‐term adherence to DOACs and clinical outcomes in real‐world clinical practice is not well understood. This study evaluated long‐term medication adherence patterns to DOAC therapy and clinical outcomes in a large US integrated health care system.

Methods and Results

We included adult patients with nonvalvular atrial fibrillation who newly initiated DOACs between 2012 and 2018 in Kaiser Permanente Southern California. Long‐term (3.5 years) adherence trajectories to DOAC were investigated using monthly proportion of days covered and group‐based trajectory models. Factors associated with long‐term adherence trajectories were investigated. Multivariable Poisson regression analyses were used to investigate thromboembolism and major bleeding events associated with long‐term adherence trajectories. Of 18 920 patients newly initiating DOACs, we identified 3 DOAC adherence trajectories: consistently adherent (85.2%), early discontinuation within 6 months (10.6%), and gradually declining adherence (4.2%). Predictors such as lower CHA₂DS₂‐VASc (0–1 versus ≥5) and previous injurious falls were associated with both early discontinuation and gradually declining adherence trajectories. Early discontinuation of DOAC therapy was associated with a higher risk of thromboembolism (rate ratio, 1.40; 95% CI, 1.05–1.86) especially after 12 months from DOAC initiation but a lower risk of major bleed compared with consistent adherence (rate ratio, 0.48; 95% CI, 0.30–0.75), specifically during the first 12 months following DOAC initiation. A gradual decline in adherence to DOACs was not statistically significantly associated with thromboembolism outcomes compared with consistent adherence.

Conclusions

Although a large proportion of patients with nonvalvular atrial fibrillation were adherent to DOAC therapy over 3.5 years, early discontinuation of DOAC was associated a higher risk of thromboembolic events. Future tailored interventions for early discontinuers may improve clinical outcomes.

Accurate Medication Adherence Measurement Using Administrative Data for Frequently Hospitalized Patients

Background: Pharmacy administrative claims data remain an accessible and efficient source to measure medication adherence for frequently hospitalized patient populations that are systematically excluded from the landmark drug trials. Published pharmacotherapy studies use medication possession ratio (MPR) and proportion of days covered (PDC) to calculate medication adherence and usually fail to incorporate hospitalization and prescription overlap/gap from claims data. To make the cacophony of adherence measures clearer, this study created a refined hospital-adjusted algorithm to capture pharmacotherapy adherence among patients with end-stage renal disease (ESRD). Methods: The United States Renal Data System (USRDS) registry of ESRD was used to determine prescription-filling patterns of those receiving new prescriptions for oral P2Y12 inhibitors (P2Y12-I) between 2011 and 2015. P2Y12-I-naïve patients were followed until death, kidney transplantation, discontinuing medications, or loss to follow-up. After flagging/censoring key variables, the algorithm adjusted for hospital length of stay (LOS) and medication overlap. Hospital-adjusted medication adherence (HA-PDC) was calculated and compared with traditional MPR and PDC methods. Analyses were performed with SAS software. Results: Hospitalization occurred for 78% of the cohort (N = 46 514). The median LOS was 12 (interquartile range [IQR] = 2-34) days. MPR and PDC were 61% (IQR = 29%-94%) and 59% (IQR = 31%-93%), respectively. After applying adjustments for overlapping coverage days and hospital stays independently, HA-PDC adherence values changed in 41% and 52.7% of the cohort, respectively. When adjustments for overlap and hospital stay were made concurrently, HA-PDC adherence values changed in 68% of the cohort by 5.8% (HA-PDC median = 0.68, IQR = 0.31-0.93). HA-PDC declined over time (3M-6M-9M-12M). Nearly 48% of the cohort had a ≥30 days refill gap in the first 3 months, and this increased over time (P < .0001). Conclusions: Refill gaps should be investigated carefully to capture accurate pharmacotherapy adherence. HA-PDC measures increased adherence substantially when adjustments for hospital stay and medication refill overlaps are made. Furthermore, if hospitalizations were ignored for medications that are included in Medicare quality measures, such as Medicare STAR program, the apparent reduction in adherence might be associated with lower quality and health plan reimbursement.

Review Article: Gastrointestinal Bleeding Risk with Direct Oral Anticoagulants

PURPOSE

Although direct oral anticoagulants (DOACs) are associated with an overall favourable safety profile, the risk of gastrointestinal bleeding with DOACs compared with vitamin K antagonists (VKAs) remains controversial. Accordingly, we aimed to provide a focused overview of the risk of gastrointestinal bleeding associated with dabigatran, rivaroxaban, apixaban and edoxaban and its management.

METHODS

We reviewed published studies reporting on DOACs with gastrointestinal bleeding as an outcome, including randomised controlled trials (RCTs), retrospective database studies and large-scale prospective cohort studies.

RESULTS

Cumulative evidence confirms no notable difference in major gastrointestinal bleeding risk between DOACs and VKAs. Moreover, gastrointestinal bleeding in DOAC-treated patients seems less severe and requires less intensive management. The main cause of upper gastrointestinal bleeding in DOAC-treated patients appears to be gastroduodenal ulcers, whereas lower gastrointestinal bleedings are mainly due to diverticula followed by angiodysplasia and haemorrhoids. The lack of head-to-head RCTs with DOACs precludes drawing conclusions on the DOAC with the lowest gastrointestinal bleeding risk. Prescribing physicians should be aware of risk factors for DOAC-related gastrointestinal bleeding (e.g. age > 65, heavy alcohol use, uncontrolled hypertension, hepatic or renal dysfunction, active cancer, anaemia) and adopt preventive measures accordingly. Management of DOAC-associated major gastrointestinal bleeding involves temporary discontinuation of the DOAC, investigation of the bleeding source and treatment of bleeding with fluid resuscitation combined with transfusion and endoscopic haemostasis.

CONCLUSION

DOACs as a class do not increase the risk of major gastrointestinal bleeding compared to VKAs, which supports their continued use for different anticoagulant indications.

Non-warfarin oral anticoagulant copayments and adherence in atrial fibrillation: A population-based cohort study

BACKGROUND

In patients with atrial fibrillation, incomplete adherence to anticoagulants increases risk of stroke. Non-warfarin oral anticoagulants (NOACs) are expensive; we evaluated whether higher copayments are associated with lower NOAC adherence.

METHODS

Using a national claims database of commercially-insured patients, we performed a cohort study of patients with atrial fibrillation who newly initiated a NOAC from 2012 to 2018. Patients were stratified into low (<$35), medium ($35-$59), or high (≥$60) copayments and propensity-score weighted based on demographics, insurance characteristics, comorbidities, prior health care utilization, calendar year, and the NOAC received. Follow-up was 1 year, with censoring for switching to a different anticoagulant, undergoing an ablation procedure, disenrolling from the insurance plan, or death. The primary outcome was adherence, measured by proportion of days covered (PDC). Secondary outcomes included NOAC discontinuation (no refill for 30 days after the end of NOAC supply) and switching anticoagulants. We compared PDC using a Kruskal-Wallis test and rates of discontinuation and switching using Cox proportional hazards models.

RESULTS

After weighting patients across the 3 copayment groups, the effective sample size was 17,558 patients, with balance across 50 clinical and demographic covariates (standardized differences <0.1). Mean age was 62 years, 29% of patients were female, and apixaban (43%), and rivaroxaban (38%) were the most common NOACs. Higher copayments were associated with lower adherence (P < .001), with a PDC of 0.82 (Interquartile range [IQR] 0.36-0.98) among those with high copayments, 0.85 (IQR 0.41-0.98) among those with medium copayments, and 0.88 (IQR 0.41-0.99) among those with low copayments. Compared to patients with low copayments, patients with high copayments had higher rates of discontinuation (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.08-1.19; P < .001).

CONCLUSIONS

Among atrial fibrillation patients newly initiating NOACs, higher copayments in commercial insurance were associated with lower adherence and higher rates of discontinuation in the first year. Policies to lower or limit cost-sharing of important medications may lead to improved adherence and better outcomes among patients receiving NOACs.

Impact of Hospitalization and Medication Switching on Post-discharge Adherence to Oral Anticoagulants in Patients With Atrial Fibrillation

BACKGROUND

Adherence to chronic medications remains poor in practice. There is limited evidence on how hospitalization affects post-discharge adherence to oral anticoagulants (OACs) in individuals with atrial fibrillation. The aim of this study was to examine the impact of hospitalization and medication switching on post-discharge adherence to OACs in the population with atrial fibrillation.

METHODS

A quasi-experimental pre-post observational study was conducted using United States commercial insurance health care claims from the 2009 to 2016 Optum database. Adults with atrial fibrillation taking OACs who had a random hospitalization occurring after the first observed OAC prescription fill and no other admission in the preceding and following 6 months were identified. OAC adherence was estimated by the proportion of days covered within 6 and 12 months before and after hospitalization. Difference-in-difference analysis was employed to compare the pre-hospitalization and post-hospitalization proportion of days covered, stratified by reasons for hospitalization (i.e., bleeding vs non-bleeding-related reasons) and adjusting for imbalanced baseline characteristics between groups. Change in adherence when the OAC was switched at discharge was also examined.

RESULTS

The 22,429 individuals who met study criteria were predominantly male (52.4%), white (77.2%), and older age (median 74 years). A clinically significant hemorrhage was the reason for 1029 (4.5%) of qualifying hospitalizations. After covariate adjustment, there was a reduction in the proportion of days covered after discharge, regardless of admission diagnosis (p<0.0001). The 6-month difference-in-difference analyses revealed that adherence was incrementally reduced by 3.2% (p=0.0003) in the bleeding group compared with the nonbleeding group, whereas switching from warfarin to a direct oral anticoagulant after hospitalization was associated with a smaller reduction by 3.4% in adherence (p=0.0342) compared with other switchers, regardless of the reason for hospitalization. The 12-month difference-in-difference analyses revealed similar results.

CONCLUSIONS

Hospitalization is temporally associated with a reduction in adherence to OACs, regardless of reason for hospitalization. More effective strategies are needed to improve OAC adherence, particularly during transition of care.

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.

[How to maintain an adherence to oral anticoagulant in a patient with atrial fibrillation?]

Less onerous, compared with warfarin, treatment with direct oral anticoagulants (DOA) can lead to better adherence to treatment of patients with atrial fibrillation (AF). However, in a certain number of patients with AF, who were recommended by DOA, cardioembolic stroke recurs, which is largely due to the patients' failure to comply with medical recommendations. The appointment of DOA as first-line drugs does not guarantee a high adherence of patients with non-valvular AF. For elderly and old patients with AF and numerous comorbidities, the proposal of a simpler pharmacotherapy regimen is especially important. In a number of large modern studies performed in clinical practice, high adherence to rivaroxaban therapy has been established, which may be a result of taking this DOA 1 time per day, its safety and effectiveness.

Modeling the impact of real-world adherence to once-daily (QD) versus twice-daily (BID) non-vitamin K antagonist oral anticoagulants on stroke and major bleeding events among non-valvular atrial fibrillation patients

OBJECTIVES

To estimate the real-world (RW) impact of adherence to once-daily (QD: rivaroxaban and edoxaban) and twice-daily (BID: apixaban and dabigatran) non-vitamin K antagonist (NOACs) on the risk of stroke and major bleeding (MB) among non-valvular atrial fibrillation (NVAF) patients.

METHODS

First, claims from the Optum Clinformatics Data Mart database (July 2012-December 2016) were analyzed. Adult NVAF patients with ≥2 NOAC dispensings (index date) were included. The relationship between NOAC adherence (proportion of days covered ≥80%) and stroke/MB 1-year post-index was evaluated using adjusted Cox proportional hazards models. Second, the natural logarithm of hazard ratios (HRs) was multiplied to a literature-derived mean adherence difference between QD and BID NOACs yielding stroke and MB rates. Third, these rates were multiplied by 1-year Kaplan-Meier rates of stroke and MB which yielded the number of strokes prevented and MBs caused. Annual cost savings were evaluated using literature-based stroke ($81,414/patient) and MB ($63,905/patient) cost estimates.

RESULTS

In total, 54,280 patients were included. HRs for adherent vs non-adherent patients were 0.67 (p < .001) for stroke and 1.09 (p = .179) for MB. The claims-derived 1-year Kaplan-Meier rates were 3.0% and 3.4% for strokes and MBs, respectively. For 100,000 AF patients, 64 strokes were prevented (p < .001), and a non-significant number of MBs (n = 15, p < .191) were caused by QD vs BID NOACs annually, which leads to cost savings estimated at $58 million for QD NOACs.

CONCLUSION

QD NOACs prevented a significant number of strokes and caused no significant increase in MBs compared to BID NOACs, which leads to significant net cost savings for NVAF patients in the US.

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.

Estimating Adherence Based on Prescription or Dispensation Information: Impact on Thresholds and Outcomes. A Real-World Study With Atrial Fibrillation Patients Treated With Oral Anticoagulants in Spain

Objective: To estimate drug exposure, Proportion of Days Covered (PDC) and percentage of patients with PDC ≥ 80% from a cohort of atrial fibrillation patients initiating oral anticoagulant (OAC) treatment. We employed three different approaches to estimate PDC, using either data from prescription and dispensing (PD cohort) or two common designs based on dispensing information only, requiring at least one (D1) or at least two (D2) refills for inclusion in the cohorts. Finally, we assessed the impact of adherence on health outcomes according to each method. Methods: Population-based retrospective cohort of all patients with Non Valvular Atrial Fibrillation (NVAF), who were newly prescribed acenocoumarol, apixaban, dabigatran or rivaroxaban from November 2011 to December 2015 in the region of Valencia (Spain). Patients were followed for 12 months to assess adherence using three different approaches (PD, D1 and D2 cohorts). To analyze the relationship between adherence (PDC ≥ 80) defined according to each method of calculation and health outcomes (death for any cause, stroke or bleeding) Cox regression models were used. For the identification of clinical events patients were followed from the end of the adherence assessment period to the end of the available follow-up period. Results: PD cohort included all patients with an OAC prescription (n = 38,802), D1 cohort excluded fully non-adherent patients (n = 265) and D2 cohort also excluded patients without two refills separated by 180 days (n = 2,614). PDC ≥ 80% ranged from 94% in the PD cohort to 75% in the D1 cohort. Drug exposure among adherent (PDC ≥ 80%) and non-adherent (PDC < 80%) patients was different between cohorts. In adjusted analysis, high adherence was associated with a reduced risk of death [Hazard Ratio (HR): from 0.82 to 0.86] and (except in the PD cohort) the risk for ischemic stroke (HR: from 0.61 to 0.64) without increasing the risk of bleeding. Conclusion: Common approaches to assess adherence using measures based on days' supply exclude groups of non-adherent patients and, also, misattribute periods of doctors' discontinuation to patient non-adherence, misestimating adherence overall. Physician-initiated discontinuation is a major contributor to reduced OAC exposure. When using the PDC80 threshold, very different groups of patients may be classified as adherent or non-adherent depending on the method used for the calculation of days' supply measures. High adherence and high exposure to OAC treatment in NVAF patients is associated with better health outcomes.

Characteristics of Apixaban-Treated Patients, Evaluation of the Dose Prescribed, and the Persistence of Treatment: A Cohort Study in Catalonia

BACKGROUND

Apixaban is a direct oral anticoagulant, which inhibits factor Xa. It has demonstrated clinical efficacy in prevention of stroke and systemic embolism in adult patients with nonvalvular atrial fibrillation and a better safety profile compared to warfarin.

OBJECTIVES

(1) To describe the characteristics of patients with nonvalvular atrial fibrillation beginning treatment with apixaban, (2) to analyze concomitant prescriptions of medications that could potentially interact with apixaban, (3) to evaluate the level of appropriate usage according to the recommended dosage, and (4) to estimate the level of apixaban persistence among naive and non-naive patients.

METHODS

Cohort study using data from primary care (System for Research in Primary Care database, users of the Institut Català de la Salut; Catalonia, Spain) from August 2013 to December 2015.

RESULTS

Mean age for apixaban-treated patients was 71.8 years (standard deviation = 11.1) and 55.6% were male. In all, 3.2% of patients receiving apixaban were taking drugs described as potentially related to either pharmacokinetic or pharmacodynamic interactions. According to the summary of product characteristics, 81.1% of patients with a recommended dose of 2.5 mg twice daily and 51.8% with a recommended dose of 5 mg twice daily actually took this dose. After 1 year of follow-up, 62.6% of the apixaban users showed good adherence.

CONCLUSION

The prescribed dose of apixaban did not fully follow the recommended dose, particularly in patients who were treatment naive. Patients with a prior history of anticoagulant treatment were more likely to remain persistent to treatment with apixaban.