Self-reported adherence to anticoagulation and its determinants using the Morisky medication adherence scale

Comparison of claims vs patient-reported adherence measures and associated outcomes among patients with nonvalvular atrial fibrillation using oral anticoagulant therapy

OBJECTIVE

To compare oral anticoagulant (OAC) adherence among patients with nonvalvular atrial fibrillation (NVAF) using patient-reported and claims-based measures, and to evaluate the effect of OAC adherence on health care costs and patient satisfaction with OAC therapy.

METHODS

This was a hybrid US observational study consisting of a longitudinal cohort survey followed by linkage and analysis of respondents' administrative claims data. Patients with NVAF receiving warfarin, dabigatran, rivaroxaban, or apixaban completed an initial survey and follow-up surveys at 4, 8, and 12 months. Patient-reported adherence was measured at each survey by Morisky Medication Adherence Scale (MMAS-8) and pharmacy claims-determined adherence by the proportion of days covered (PDC) for the 12-month period following the initial survey date; adherence was defined as MMAS-8 score =8 and PDC ≥80%. Patient satisfaction with OAC therapy was assessed by the Duke Anticoagulation Satisfaction Scale (DASS).

RESULTS

Overall, 675 patients completed at least the initial survey (warfarin, n=271; dabigatran, n=266; rivaroxaban, n=128; apixaban, n=10). Fewer than half (47.9%) were PDC adherent, 37.2% were MMAS-8 adherent, and 19.4% were adherent by both measures. Total medical costs of PDC-adherent patients were significantly lower vs PDC-nonadherent patients (US$640 vs $993 per-patient per-month, respectively, p<0.05). MMAS-8-adherent patients reported higher treatment satisfaction; total DASS score was significantly lower among MMAS-8-adherent than MMAS-8-nonadherent patients (37.3 vs 42.9, respectively, p<0.001).

CONCLUSION

Using claims-based or patient-reported methods to measure OAC adherence may lead to different results when assessing impact on health care costs and satisfaction with anticoagulation medication. These results underscore the importance of considering both claims-based and patient-reported measures when evaluating treatment adherence in real-world settings.

Real-life experience of quality of life, treatment satisfaction, and adherence in patients receiving oral anticoagulants for atrial fibrillation

INTRODUCTION

Direct oral anticoagulants (DOACs) have shown noninferiority to vitamin K antagonists (VKA) in stroke prevention in patients with atrial fibrillation. DOAC treatment may be less demanding than VKA, improving quality of life. To date, there have been no studies of the real-life experience of outpatients receiving anticoagulation therapy for atrial fibrillation in France.

METHODS

An observational descriptive real-life epidemiological study used three validated questionnaires (EQ-5D, PACT-Q2, and MMAS-8 French Translation) to assess quality of life, treatment satisfaction, and adherence, respectively, in 200 patients managed on an outpatient basis for atrial fibrillation who were receiving anticoagulation therapy by VKA or DOAC for at least 3 months. Patients were distributed between four groups: primary VKA (P-VKA), switch from VKA to DOAC (S-DOAC), primary DOAC (P-DOAC), and switch from DOAC to VKA (S-VKA).

RESULTS

Two hundred patients responded to the questionnaires: 89, 50, 52, and 9 in the P-VKA, S-DOAC, P-DOAC and S-VKA groups, respectively. Only the first three groups were compared statistically, because of the small size of the S-VKA group. Quality of life and satisfaction were good in all three groups, with no significant difference in quality of life but significantly greater satisfaction with respect to the "convenience" and "satisfaction" dimensions for DOACs (S-DOAC and P-DOAC groups versus P-VKA group; p<0.001, for both dimensions). Adherence did not significantly differ between groups.

CONCLUSION

The experience of patients under oral anticoagulation therapy for atrial fibrillation managed on an outpatient basis was good, with comparable quality of life under DOACs and VKA, and significantly greater satisfaction under DOACs, without impact on adherence. Taking account of patient preference in "shared decision-making" for the choice of type of anticoagulant could improve the patients' experience of treatment.

Pharmacists' confidence when providing pharmaceutical care on anticoagulants, a multinational survey

Background Guidelines on the management of orally anticoagulated patients are continuously evolving, leading to an increased need for pharmacists to be fully integrated in care provision. Objective To identify self-reported gaps in confidence among practicing pharmacists in the area of anticoagulation. Setting Pharmacists in different work settings in different countries. Method Cross-sectional international survey from October 2015 till November 2016 among pharmacists working in different settings to assess their level of confidence when delivering anticoagulants as well as to identify possible educational needs regarding this medication class. Validation of the survey was ensured. Results Responses from 4212 pharmacists originating from 18 countries were obtained. Pharmacists' level of confidence was significantly higher (p < 0.001) when advising patients on vitamin K antagonists (VKAs) versus non-vitamin K antagonists (NOACs). In general, hospital pharmacists displayed higher confidence levels compared to community pharmacists when advising patients on anticoagulation (p < 0.001). Two distinct patterns of confidence levels emerged relating to basic and advanced pharmaceutical care. Confidence levels when providing advanced pharmaceutical care were significantly higher for Oceania and lower for South America (p < 0.005). Conclusions Pharmacists felt more confident in supporting patients receiving VKAs compared to the more recently introduced NOACs. With the increasing use of NOACs and the risks pertaining to anticoagulation therapy, it is essential to invest in education for pharmacists to address their knowledge gaps enabling them to confidently support patients receiving oral anticoagulants.

Elective Cardioversion in the Era of Novel Oral Anticoagulants - Does a Nurse Administered Verbal Questionnaire for Compliance Negate the Need for Routine Transoesophageal Echocardiography?

BACKGROUND

Anticoagulation prior to elective external direct current cardioversion (EDCCV) is mandatory. The inability to monitor compliance with novel oral anticoagulants (NOACs) raises a potential safety issue. We aimed to evaluate whether a structured, nurse-led assessment of compliance prior to EDCCV ensures safety without the need for routine transoesophageal echocardiography (TOE).

METHODS

Data was prospectively collected on consecutive patients undergoing EDCCV during 2014-2015. All procedures were supervised by an electrophysiology clinical nurse consultant (EPCNC). Drug compliance was verbally assessed using a standardised questionnaire by the EPCNC. Novel oral anticoagulants compliance was required for a continuous period of 3 weeks prior to EDCCV; otherwise a TOE-guided EDDCV was performed. All patients had follow-up 30 days post-procedure.

RESULTS

Three hundred and eleven cardioversions were performed on 256 patients in whom 154 (49.5%) were prescribed a NOAC (rivaroxaban (n=105; 68.2%), dabigatran (n=38; 24.7%), apixaban (n=11; 7.1%)). Median age was 63 years (24-94 yrs), mean CHADS₂-Vasc score was 2.0±1.5 and 138 (89.6%) were outpatients. One hundred and twenty-nine (83.8%) EDCCV were for atrial fibrillation and 25 (16.2%) for atrial flutter. Sinus rhythm was achieved in 90.3% of cases. Fourteen patients (9%) assessed as non-compliant underwent TOE. 129 (83.8%) EDCCV were performed without prior TOE. No stroke or systemic embolism was identified in any patient treated with either warfarin or a NOAC.

CONCLUSIONS

A standardised, verbal questionnaire can be administered to detect NOAC non-compliance in patients undergoing EDCCV. With appropriate compliance assessment a nurse-led EDCCV without routine TOE did not significantly compromise safety in this study group.

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.

Self-Reported Adherence to Capecitabine on XELOX Treatment as Adjuvant Therapy for Colorectal Cancer

Adherence has become an important issue in modern oncology treatment. Most studies have included heterogeneous target tumor types, regimens, and therapy settings. Our study focused on capecitabine during capecitabine plus oxaliplatin (XELOX) treatment as an adjuvant therapy for colorectal cancer. The main aims of this study were to evaluate real-life adherence to capecitabine and to investigate candidate factors that might decrease adherence. We studied 338 consecutive patients who received XELOX treatment between December 1, 2011, and April 30, 2015, at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research. Our study assessed adherence to capecitabine through patient-reported treatment diaries and interviewed nonadherents to determine the reasons for not taking capecitabine at a pharmaceutical outpatient clinic. We calculated the adherence rate in a cycle as: number of times the patient took capecitabine/28. Relative dose intensities and factors associated with deteriorating adherence to capecitabine were retrospectively surveyed from electronic patient records. Uni- and multivariate logistic regression analyses were used to investigate factors associated with optimal adherence. The study covered 282 patients who received 2,055 cycles of XELOX. Median adherence rate was 94.0% in the first cycle, and median relative dose intensity of capecitabine was 77.8%. The most common reasons for nonadherence were nausea/vomiting and diarrhea. The presence of the following factors was not significantly associated with adherence: ECOG performance status ≥1 (p = 0.715), clinical stage (p = 0.408), primary tumor site (p = 0.576), age ≥70 years at study entry (p = 0.757), female gender (p = 0.504), and not living alone (p = 0.579). The adherence rate from this study was significantly higher than the adherence from metastatic settings. Adherence-enhancing interventions for capecitabine in XELOX treatment as adjuvant therapy comprised management of nausea/vomiting and diarrhea.

The role of Patient Health Engagement Model (PHE-model) in affecting patient activation and medication adherence: A structural equation model

BACKGROUND

Increasing bodies of scientific research today examines the factors and interventions affecting patients' ability to self-manage and adhere to treatment. Patient activation is considered the most reliable indicator of patients' ability to manage health autonomously. Only a few studies have tried to assess the role of psychosocial factors in promoting patient activation. A more systematic modeling of the psychosocial factors explaining the variance of patient activation is needed.

OBJECTIVE

To test the hypothesized effect of patient activation on medication adherence; to test the the hypothesized effects of positive emotions and of the quality of the patient/doctor relationship on patient activation; and to test the hypothesized mediating effect of Patient Health Engagement (PHE-model) in this pathway.

MATERIAL AND METHODS

This cross-sectional study involved 352 Italian-speaking adult chronic patients. The survey included measures of i) patient activation (Patient Activation Measure 13 -short form); ii) Patient Health Engagement model (Patient Health Engagement Scale); iii) patient adherence (4 item-Morinsky Medication Adherence Scale); iv) the quality of the patients' emotional feelings (Manikin Self Assessment Scale); v) the quality of the patient/doctor relationship (Health Care Climate Questionnaire). Structural equation modeling was used to test the hypotheses proposed.

RESULTS

According to the theoretical model we hypothesized, research results confirmed that patients' activation significantly affects their reported medication adherence. Moreover, psychosocial factors, such as the patients' quality of the emotional feelings and the quality of the patient/doctor relationship were demonstrated to be factors affecting the level of patient activation. Finally, the mediation effect of the Patient Health Engagement model was confirmed by the analysis.

CONCLUSIONS

Consistently with the results of previous studies, these findings demonstrate that the Patient Health Engagement Model is a critical factor in enhancing the quality of care. The Patient Health Engagement Model might acts as a mechanism to increase patient activation and adherence.

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.

NOACs for treatment of venous thromboembolism in clinical practice

Randomised controlled trials have provided important information on the efficacy and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) for treatment of venous thromboembolism (VTE), leading to registration and increasing use in clinical practice. Many questions remain to be answered, and observational studies are often more suitable for answering "real-world" questions than randomised controlled trials. Patient satisfaction, quality of life, and adherence and persistence in clinical practice with the drug regimen can only be assessed with an open-label design. Evaluation of risk for long-term sequelae of the disease requires much longer follow-up than is possible in registration trials. Treatment patterns and utilisation of health care resources can be assessed from observations in the clinical practice setting. We will review published as well as currently active observational studies with NOACs in VTE, with or without a comparator anticoagulant. These studies are based on cohorts of different sizes, registries, or administrative health care databases. We will also discuss some limitations in analysis and interpretation of observational studies.

Drug Adherence in Patients With Nonvalvular Atrial Fibrillation Taking Non-Vitamin K Antagonist Oral Anticoagulants in Turkey: NOAC-TR

Adherence to non-vitamin K antagonist oral anticoagulants (NOACs) is an important factor for ensuring efficacy and safety in nonvalvular atrial fibrillation (NVAF). There are controversial results regarding NOAC adherence in real-world data and there are no data about NOAC adherence in Turkish population. This study investigated the NOAC adherence based on self-report, factors affecting nonadherence, and the relation of the adherence level with efficacy and safety outcomes. This multicenter cross-sectional study included 2738 patients (59% female) using NOAC (dabigatran, apixaban, and rivaroxaban) due to NVAF for more than 3 months with >30 days of supply between September 1, 2015, and February 28, 2016. To measure the adherence level, an 8-item Morisky Medication Adherence Scale was used. The mean age of the patients was 70 ± 10 years. Of the 2738 patients, 44% were receiving dabigatran, 38% rivaroxaban, and 18% apixaban. A total of 630 (23%) patients had high medication adherence, 712 (26%) moderate adherence, and 1396 (51%) low adherence. Nonadherence had related to stroke (5.6% vs 2.5%, P < .001) and minor (21.2% vs 11.1%, P < .001) and major (6.1% vs 3.7%, P = .004) bleeding rates. The adherence to NOAC was found to be quite low in Turkey. Nonadherence is associated with bleeding and thromboembolic cardiovascular events. Age, taking NOAC twice a day, and the additional noncardiac diseases, depression, and dementia were the independent factors affecting poor medication adherence.

Assessment of quality of life, satisfaction with anticoagulation therapy, and adherence to treatment in patients receiving long-course vitamin K antagonists or direct oral anticoagulants for venous thromboembolism

INTRODUCTION

Direct oral anticoagulants (DOACs) have shown non-inferiority and ease of use compared to vitamin K antagonists (VKA) in the treatment of venous thromboembolism (VTE). No study so far has been directed toward real-life experience of outpatients receiving anticoagulants for VTE in France.

METHODS

This is an observational descriptive real-life epidemiological study, using three validated questionnaires (Morisky Medication Adherence Scale-8, EQ-5D, and part 2 of the Perception of Anticoagulant Treatment Questionnaire), to assess adherence, quality of life, and satisfaction in 100 VTE outpatients receiving anticoagulation therapy by VKA (primary or switched from DOAC to VKA) or by DOAC (primary or switched from VKA to DOAC).

RESULTS

Patients were very much satisfied with their treatment in both DOAC and VKA groups. Despite advantages of DOACs, therapeutic adherence was only moderate. The best adherence scores were observed in the primary VKA switched to DOAC for at least 3 months (S-DOAC) subgroup. Quality of life was better in the DOAC group mainly because of the absence of the requirement for blood testing. Most of the complaints concerned the pain/discomfort dimension in the VKA group and anxiety/depression dimension in the DOAC group.

CONCLUSION

Patients were satisfied with their anticoagulant treatment, especially when they were involved in choosing the anticoagulant, and the treatment suited them. Quality of life of patients in the DOAC group was better than in the VKA group, but adherence remains to be improved. This study highlights the importance of the physician-patient relationship, pretreatment initiation, and follow-up of any anticoagulation therapy throughout.

Adherence to medication and characteristics of Japanese patients with non-valvular atrial fibrillation

BACKGROUND

Adherence to medication plays an important role in the prevention of morbidity and mortality in non-valvular atrial fibrillation (NVAF) patients. The aim of this study is to assess adherence to medication and risk factors for non-adherence in Japanese NVAF patients who are prescribed anticoagulants.

METHODS

A total of 378 outpatients with NVAF who completed self-reported questionnaires were analyzed in this prospective study (mean age 69±12 years; 26% female). Self-reported adherence to cardiovascular drugs including anticoagulants was measured with a modified Siegal scale. Depression was defined as a Patient Health Questionnaire-9 score of ≥10. Univariate and multivariate analyses were performed on several variables to analyze factors affecting non-adherence.

RESULTS

In total, 291 (77%) of our patients received warfarin, and the remainder received direct oral anticoagulants. Fifty-two (14%) patients were defined as non-adherent. Univariate analyses showed that age <65 years, ≥2 times daily dosing of cardiovascular drugs and employment, but not depression, were significantly associated with non-adherence, 1.87 (95% CI: 1.01-3.42, p=0.04), 2.97 (95% CI: 1.64-5.49, p<0.01), 2.11 (95% CI: 1.16-3.93, p=0.01), and 0.74 (95% CI: 0.26-2.64), respectively. Multivariate analysis showed that only ≥2 times daily dosing was a significant independent risk factor (HR 3.06, 95% CI: 1.67-5.69, p<0.01).

CONCLUSIONS

Our study showed that the prevalence of non-adherence to medications was 14% in NVAF patients. Frequent daily dosing was an independent risk factor for non-adherence to medication (UMIN-CTR No. UMIN 000023514).

An update on the pharmaceutical management of thrombosis

INTRODUCTION

Anticoagulants such as heparins and vitamin K antagonists (VKA) are effective for thrombosis prevention and treatment, but are associated with the risk of bleeding and other limitations, spurring the search for improved drugs. Areas covered: to evaluate the newer anticoagulants, focusing on those tested in phase III clinical trials such as direct oral anticoagulants (DOACs), antisense oligonucleotides (ASO) and warfarin analogues. DOACs such as dabigatran, rivaroxaban, apixaban and edoxaban are licensed for stroke prevention in atrial fibrillation and treatment of venous thromboembolism, dabigatran, rivaroxaban and apixaban for postoperative thromboprophylaxis in patients undergoing elective hip or knee arthroplasty and rivaroxaban for secondary prevention of acute coronary syndromes. ASO interfering with Factor XI hepatic synthesis were effective and safe for thromboprophylaxis in elective knee arthroplasty. Expert opinion: DOACs have overcome some limitations of anticoagulants such as VKA, but are still associated with a risk of bleeding and they lack both standardized and widely available tests measuring their anticoagulant effect and a reversal agent, except for idarucizumab, specific for dabigatran, in case of major or life threatening bleeding or emergency surgery. Agents targeting Factor XI and possibly Factor XII may be ideal anticoagulants, as they can prevent thrombosis with low bleeding risk.

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.

Comparison of Medication Adherence and Treatment Persistence between New Oral Anticoagulant and Warfarin among Patients

Introduction: This study aimed to compare medication adherence and treatment persistence of patients on warfarin versus rivaroxaban in Singapore. A secondary objective was to identify significant covariates influencing adherence. Materials and Methods: A retrospective cohort study was conducted where data from September 2009 to October 2014 was retrieved from the hospital electronic databases. Prescription records of rivaroxaban patients with 3 months or more of continuous prescription were extracted and compared against those of patients on warfarin. Primary outcome of adherence was determined based on the medication possession ratio (MPR), while treatment persistence was determined by outpatient clinic appointment gaps. Results: A total of 94 rivaroxaban and 137 warfarin users were analysed by complete case analysis. The MPR of warfarin patients was lower than rivaroxaban patients by 10% (95% CI, 6.4% to 13.6%; P <0.0001). Also, there were more warfarin patients who had gaps in treatment persistence compared to those prescribed rivaroxaban (8.0% vs 1.1%; P = 0.03). Significant factors affecting medication adherence were age and duration of anticoagulant use. For every 10-year increase in age, MPR increased by 1.7% (95% CI, 0.7% to 2.8%). Similarly, for every year increase in duration of use, MPR increased by 1.8% (95% CI, 0.6% to 3.0%). Race, gender, concomitant medication and type of residence were not found to be significant covariates in the multivariable analysis. Conclusion: Patients on rivaroxaban are likely to be more adherent to their prescribed oral anticoagulant with increasing age and duration of treatment influencing adherence. Key words: Compliance, Medication possession ratio, Oral anticoagulation, Rivaroxaban

Reducing the risk of venous thromboembolism using apixaban - patient perspectives and considerations. Should more attention be given to females?

BACKGROUND

New oral anticoagulant agents, such as apixaban, rivaroxaban, dabigatran, or endoxaban, have recently become for patients an alternative option to conventional treatment in the therapy of venous thromboembolism (VTE). Thus, we aimed to review the available information on adverse events (AEs) of apixaban compared to conventional therapy (heparin or vitamin K antagonists) in randomized controlled trials (RCTs) on patients treated for VTE, with a particular attention to sex subgroups.

METHODS

An electronic search in MEDLINE and Embase was performed by using the keywords "apixaban" and "venous thromboembolism". All RCTs focused on apixaban in the treatment and prevention of VTE were evaluated for the presence of AEs. AEs were classified as serious, bleeding, and cause of discontinuation. Moreover, we also searched by using the keywords "gender" and "venous thromboembolism" and "anticoagulants".

RESULTS

Considering all subjects enrolled in the eleven RCTs as a whole to investigate the occurrence of AEs, we extrapolated an events/subjects rate of 57.8% for AEs (6,445/11,144), 7.7% for serious AEs (975/12,647), 9.1% for bleeding events (1,229/13,454), and 3.2% for discontinuation of apixaban (421/13,039). The percentage of AEs was lower in subjects treated with apixaban than in those treated with conventional VTE therapy (53% vs 56.3%, respectively). However, only one study provided data on separate analysis by sex of either efficacy or safety of apixaban.

CONCLUSION

Under the patient's perspective, apixaban could represent a good choice in the treatment of VTE, due to its pharmacological, economical, and safety profile. These positive aspects are certainly present in both sexes, since the available studies include a correct percentage of women, but data with separate analyses by sex are extremely limited. Future clinical trials should include in their results on clinical impact and outcomes a stratification by sex, and studies aimed to evaluate possible sex-related differences for these drugs should be strongly encouraged.