Stop the clots, but at what cost? Pharmacoeconomics of dabigatran etexilate for the prevention of stroke in subjects with atrial fibrillation: a systematic literature review

Quality of anticoagulation with warfarin in rural Chhattisgarh, India

Background & objectives

In most of rural India, warfarin is the only oral anticoagulant available. Among patients taking warfarin, there is a strong association between poor control of the international normalized ratio (INR) and adverse events. This study was aimed to quantify INR control in a secondary healthcare system in rural Chhattisgarh, India.

Methods

The INR data were retrospectively obtained from all patients taking warfarin during 2014-2016 at a secondary healthcare system in rural Chhattisgarh, India. Patients attending the clinic had their INR checked at the hospital laboratory and their warfarin dose adjusted by a physician on the same day. The time in therapeutic range (TTR) was calculated for patients who had at least two INR visits.

Results

The 249 patients had 2839 INR visits. Their median age was 46 yr, and the median body mass index was 17.7 kg/m^[2]. They lived a median distance of 78 km (2-3 h of travel) from the hospital. The median INR was 1.7 for a target INR of 2.0-3.0 (n=221) and 2.1 for a target of 2.5-3.5 (n=28). The median TTR was 13.0 per cent, and INR was subtherapeutic 66.0 per cent of the time. Distance from the hospital was not correlated with TTR.

Interpretation & conclusions

INR values were subtherapeutic two-thirds of the time, and TTR values were poor regardless of distance from the health centre. Future studies should be done to identify interventions to improve INR control.

Cost-effectiveness Evaluations Among the Direct Oral Anticoagulants for the Prevention and Treatment of Venous Thromboembolism: Systematic Review

Venous thromboembolism (VTE) is associated with high recurrence, mortality, and cost burden. Direct oral anticoagulants (DOACs) are currently used for VTE treatment, and they offer more benefits over warfarin, despite being more expensive. There is no consensus on the most cost-effective DOAC agent, especially in VTE. This systematic review aims to summarize the comparative cost-effectiveness studies and their impact among DOACs in the treatment of VTE. Literature systematic review of PubMed, Embase, and EconLit was conducted in February 2018 to identify all cost-effectiveness studies of DOAC for the treatment and prevention of VTE. Two independent investigators systematically collected search results and assessed the quality of the studies. The search identified 7 articles, all of which had dabigatran and rivaroxaban as comparators, 6 of which also included apixaban, and 2 of which also had edoxaban. Results of 3 articles concluded that apixaban is a dominant strategy compared to other DOACs in terms of Incremental Cost-Effectiveness Ratio (ICER) in the treatment and prevention of recurrent VTE. One article compared rivaroxaban and dabigatran, with the latter dominating rivaroxaban in terms of ICER. Compared to other DOACs, 2 articles reported apixaban being associated with highest annual total medical cost avoidance of US$4244 and US$4440 per patient-year (ppy), respectively. One article reported that apixaban had the highest annual total medical cost differences of US$918 ppy compared to other DOACs. This systematic review demonstrates that apixaban is considered a cost-effective strategy for VTE treatment and prevention of recurrent VTE.

Effects of policy interventions on the introduction of novel oral anticoagulants in Stockholm: an interrupted time series analysis

AIMS

The aim of the present study was to assess the effect of policy interventions - i.e. reimbursement decisions, guidelines and regional recommendations - on the prescribing of oral anticoagulant treatment in patients with atrial fibrillation (AF).

METHODS

Interrupted time series analyses were carried out using monthly data on all patients with a recorded diagnosis of AF newly initiated (switchers and anticoagulant-naïve patients alike) on warfarin, dabigatran, rivaroxaban or apixaban in the Stockholm region from April 2011 until February 2016.

RESULTS

A total of 34 165 initiations in 27 942 patients were included. The publication of the European Guidelines was associated with an increase in novel oral anticoagulant (NOAC) initiations of 12.5% [95% confidence interval (CI) 7.3, 17.7] after 5 months. The choice between the different NOACs was mainly associated with changes in the regional recommendations, with apixaban initiations increasing by 19.5% (95% CI 16.3, 22.7) 5 months after the drug was recommended as a first-line alternative to warfarin. Dabigatran received a second-line recommendation but initiations decreased by -9.5% (95% CI -12.6, -6.4), and initiations of rivaroxaban, which had no specific recommendation, decreased by -9.2% (95% CI -12.7, -5.7). A steady decrease in warfarin and increase in NOAC initiations was seen throughout the study period and from November 2015, AF patients were more likely to receive apixaban than any other anticoagulant, while less than 20% of the initiations were with warfarin.

CONCLUSIONS

After reimbursement and inclusion in the European guidelines, the NOACs started gaining in popularity, while changes in regional recommendations were associated with the biggest change in prescribers' choice between the different NOACs.

Clinical utility of dabigatran in United Arab Emirates. A pharmacovigilance study

Objectives:

To provide early data regarding clinical utility of dabigatran in Al-Ain, United Arab Emirates (UAE).

Methods:

This was an ethics approved retrospective cross sectional study. We retrieved a total of 76 patients who were using dabigatran from September to December 2014 in the Cardiology Clinic at Al-Ain Hospital, Al-Ain, UAE. The primary analysis was designed to test the frequency of bleeding events (rate) with dabigatran 75, 110, and 150 mg.

Results:

The mean age ± standard deviation of cohort was 67.9 ± 1.5 years (range; 29-98 years), composed of males (52.6%) with mean age of 66.3 ± 1.7 years, and females (47.4%) with mean age of 69.6 ± 1.1 years. The highest age group was those between 61-80 years (60.5%). Most comprised the age strata of ≤75 years (73.7%). The main indication for dabigatran use was atrial fibrillation. The rate of bleeding with dabigatran was 18/76 (23.7%), and melena was the leading cause of bleeding 8/76 (10.7%). The hospitalization rate was 67.1%, dabigatran withdrawal rate was 0.01%, and mortality rate was 6.5%. The cohort had exhibited incidences of minor bleeding with one fatal major bleeding, high co-morbidities, admission, and readmission, which was not directly linked to dabigatran. We did not identify any relation of death due to dabigatran.

Conclusion:

Dabigatran is a suitable alternative to warfarin obviating the need for repetitive international normalized ratio monitoring, however, it may need plasma drug monitoring.

Dabigatran - a continuing exemplar case history demonstrating the need for comprehensive models to optimize the utilization of new drugs

Background: There are potential conflicts between authorities and companies to fund new premium priced drugs especially where there are effectiveness, safety and/or budget concerns. Dabigatran, a new oral anticoagulant for the prevention of stroke in patients with non-valvular atrial fibrillation (AF), exemplifies this issue. Whilst new effective treatments are needed, there are issues in the elderly with dabigatran due to variable drug concentrations, no known antidote and dependence on renal elimination. Published studies showed dabigatran to be cost-effective but there are budget concerns given the prevalence of AF. These concerns resulted in extensive activities pre- to post-launch to manage its introduction.

Objective: To (i) review authority activities across countries, (ii) use the findings to develop new models to better manage the entry of new drugs, and (iii) review the implications based on post-launch activities.

Methodology: (i) Descriptive review and appraisal of activities regarding dabigatran, (ii) development of guidance for key stakeholder groups through an iterative process, (iii) refining guidance following post launch studies.

Results: Plethora of activities to manage dabigatran including extensive pre-launch activities, risk sharing arrangements, prescribing restrictions and monitoring of prescribing post launch. Reimbursement has been denied in some countries due to concerns with its budget impact and/or excessive bleeding. Development of a new model and future guidance is proposed to better manage the entry of new drugs, centering on three pillars of pre-, peri-, and post-launch activities. Post-launch activities include increasing use of patient registries to monitor the safety and effectiveness of new drugs in clinical practice.

Conclusion: Models for introducing new drugs are essential to optimize their prescribing especially where concerns. Without such models, new drugs may be withdrawn prematurely and/or struggle for funding.

Dabigatran - a case history demonstrating the need for comprehensive approaches to optimize the use of new drugs

BACKGROUND

There are potential conflicts between authorities and companies to fund new premium priced drugs especially where there are safety and/or budget concerns. Dabigatran, a new oral anticoagulant for the prevention of stroke in patients with non-valvular atrial fibrillation (AF), exemplifies this issue. Whilst new effective treatments are needed, there are issues in the elderly with dabigatran due to variable drug concentrations, no known antidote and dependence on renal elimination. Published studies have shown dabigatran to be cost-effective but there are budget concerns given the prevalence of AF. There are also issues with potentially re-designing anticoagulant services. This has resulted in activities across countries to better manage its use.

OBJECTIVE

To (i) review authority activities in over 30 countries and regions, (ii) use the findings to develop new models to better manage the entry of new drugs, and (iii) review the implications for all major stakeholder groups.

METHODOLOGY

Descriptive review and appraisal of activities regarding dabigatran and the development of guidance for groups through an iterative process.

RESULTS

There has been a plethora of activities among authorities to manage the prescribing of dabigatran including extensive pre-launch activities, risk sharing arrangements, prescribing restrictions, and monitoring of prescribing post-launch. Reimbursement has been denied in some countries due to concerns with its budget impact and/or excessive bleeding. Development of a new model and future guidance is proposed to better manage the entry of new drugs, centering on three pillars of pre-, peri-, and post-launch activities.

CONCLUSION

Models for introducing new drugs are essential to optimize their prescribing especially where there are concerns. Without such models, new drugs may be withdrawn prematurely and/or struggle for funding.