Using triple antiplatelet therapy in patients with non-ST elevation acute coronary syndrome managed invasively: a cost-effectiveness analysis

Cost-effectiveness Analysis of Rivaroxaban in the Secondary Prevention of Acute Coronary Syndromes in Sweden

BACKGROUND

Worldwide, coronary heart disease accounts for 7 million deaths each year. In Sweden, acute coronary syndrome (ACS) is a leading cause of hospitalization and is responsible for 1 in 4 deaths.

OBJECTIVE

The aim of this analysis was to assess the cost-effectiveness of rivaroxaban 2.5 mg twice daily (BID) in combination with standard antiplatelet therapy (ST-APT) versus ST-APT alone, for the secondary prevention of ACS in adult patients with elevated cardiac biomarkers without a prior history of stroke/transient ischemic attack (TIA), from a Swedish societal perspective, based on clinical data from the global ATLAS ACS 2-TIMI 51 trial, literature-based quality of life data and costs sourced from Swedish national databases.

METHODS

A Markov model was developed to capture rates of single and multiple myocardial infarction (MI), ischemic and hemorrhagic stroke, thrombolysis in myocardial infarction (TIMI) major, minor, and "requiring medical attention" bleeds, revascularization events, and associated costs and utilities in patients who were stabilized after an initial ACS event. Efficacy and safety data for the first 2 years came from the ATLAS ACS 2-TIMI 51 trial. Long-term probabilities were extrapolated using safety and effectiveness of acetylsalicylic acid data, which was estimated from published literature, assuming constant rates in time. Future cost and effects were discounted at 3.0%. Univariate and probabilistic sensitivity analyses were conducted.

RESULTS

In the base case, the use of rivaroxaban 2.5 mg BID was associated with improvements in survival and quality-adjusted life years (QALYs), yielding an incremental cost per QALY of 71,246 Swedish Krona (SEK) (€8045). The outcomes were robust to changes in inputs. The probabilistic sensitivity analysis demonstrated rivaroxaban 2.5 mg BID to be cost-effective in >99.9% of cases, assuming a willingness-to-pay threshold of SEK 500,000 (€56,458).

CONCLUSION

Compared with ST-APT alone, the use of rivaroxaban 2.5 mg BID in combination with ST-APT can be considered a cost-effective treatment option for ACS patients with elevated cardiac biomarkers without a prior history of stroke/TIA in Sweden.

FUNDING

Bayer Pharma AG.

Cost effectiveness of treatments for non-ST-segment elevation acute coronary syndrome

BACKGROUND

Acute coronary syndrome (ACS) represents the most common subset of cardiovascular heart diseases and relates to high rates of morbidity and mortality worldwide and, consequently, to both the direct and indirect costs to the health system and society. Given the rising healthcare costs combined with budgetary constraints, health care systems and decision makers are faced with challenging decisions and the need to choose alternative treatments that not only improve patient quantity and quality of life but are also economically attractive.

OBJECTIVES

To systematically review the published literature and to identify studies evaluating the cost effectiveness of different treatments for patients presenting with non-ST-segment elevation (NSTE) ACS.

DATA SOURCES

A literature search was performed using PubMed and the Cochrane Library until October 2013, with no limit on publication date.

STUDY SELECTION

The search was conducted using predetermined inclusion and exclusion criteria, limiting articles to those published in the English language and those reporting results of economic evaluations [i.e. cost-effectiveness (CEA), cost-utility (CUA) cost-minimisation (CMA) cost-consequence (CCA) and cost-benefit (CBA) analyses] of the different treatment therapies used for managing patients presenting with NSTE-ACS. Publications such as editorials, letters to the editor, posters, expert opinions, reviews, systematic reviews, or meta-analyses were excluded.

STUDY APPRAISAL METHODS

All studies included were assessed for their methodological quality using the British Medical Journal checklist.

RESULTS

A total of 39 studies were included, presenting a wide variation in terms of methodological approaches and settings, thus resulting in different ranges of incremental cost-effectiveness ratios for each treatment evaluated.

CONCLUSIONS

Evidence from the present systematic review suggests that the majority of the available treatments represent either cost-saving or cost-effective options for NSTE-ACS patients. Moreover, the cost effectiveness of the available treatments was found to be dependent on various factors, particularly the risk profile of patients and the cost of treatment, and hence there is a need to take these into consideration when making decisions and choices.

A systematic review of the quality of economic models comparing thrombosis inhibitors in patients with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

Thrombosis inhibitors can be used to treat acute coronary syndromes (ACS). However, there are various alternative treatment strategies, of which some have been compared using health economic decision models.

OBJECTIVE

To assess the quality of health economic decision models comparing thrombosis inhibitors in patients with ACS undergoing percutaneous coronary intervention, and to identify areas for quality improvement.

DATA SOURCES

The literature databases MEDLINE, EMBASE, EconLit, National Health Service Economic Evaluation Database (NHS EED), Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA).

STUDY APPRAISAL AND SYNTHESIS METHODS

A review of the quality of health economic decision models was conducted by two independent reviewers, using the Philips checklist.

RESULTS

Twenty-one relevant studies were identified. Differences were apparent regarding the model type (six decision trees, four Markov models, eight combinations, three undefined models), the model structure (types of events, Markov states) and the incorporation of data (efficacy, cost and utility data). Critical issues were the absence of particular events (e.g. thrombocytopenia, stroke) and questionable usage of utility values within some studies.

LIMITATIONS

As we restricted our search to health economic decision models comparing thrombosis inhibitors, interesting aspects related to the quality of studies of adjacent medical areas that compared stents or procedures could have been missed.

CONCLUSIONS

This review identified areas where recommendations are indicated regarding the quality of future ACS decision models. For example, all critical events and relevant treatment options should be included. Models also need to allow for changing event probabilities to correctly reflect ACS and to incorporate appropriate, age-specific utility values and decrements when conducting cost-utility analyses.

Cost-effectiveness of 12-month treatment with ticagrelor compared with clopidogrel in the management of acute coronary syndromes

BACKGROUND

The PLATO (Platelet Inhibition and Patient Outcomes) randomized trial (NCT00391872) in patients with acute coronary syndromes (ACS) reported that ticagrelor (in addition to aspirin) reduced the rate of the composite end point of myocardial infarction (MI), stroke, or cardiovascular death compared with clopidogrel (in addition to aspirin) by 16% over 12 months (P < 0.001). No significant difference in the incidence of major bleeding was noted, but ticagrelor was associated with a higher rate of major bleeding not related to coronary artery bypass grafting.

OBJECTIVE

By extrapolating the key findings of PLATO, we sought to assess the cost-effectiveness of ticagrelor compared with clopidogrel in the management of ACS in a contemporary Australian setting.

METHODS

A Markov model with 4 health states (free from further ACS events, MI, stroke, and death) was developed to simulate the long-term costs and outcomes associated with ACS. Event risks were based on data derived directly from PLATO, and costs and utilities were drawn from published sources. A 10-year time horizon was simulated, and future costs and benefits were discounted at a 5% annual rate. However, treatment with ticagrelor and clopidogrel was only assumed for the first 12 months, with no benefits applied beyond drug cessation. Sensitivity analyses were undertaken based on variations to key data inputs. All costs for resource use applied in the analysis were based on published Australian prices (in 2010/2011 dollars [A$]).

RESULTS

Over 10 years, the estimated quality-adjusted life-years lived per-patient were 5.74 and 5.68 for ticagrelor and clopidogrel, respectively. Net costs were A$19,132 for ticagrelor and A$18,428 for clopidogrel. These equated to an incremental cost-effectiveness ratio of A$9031 per quality-adjusted life-year gained for ticagrelor compared with clopidogrel. Sensitivity analyses indicated the result to be robust.

CONCLUSIONS

When assessed from the perspective of the Australian health care system, ticagrelor is likely to be cost-effective compared with clopidogrel in preventing downstream morbidity and mortality associated with ACS.

Model performance evaluation (validation and calibration) in model-based studies of therapeutic interventions for cardiovascular diseases : a review and suggested reporting framework

Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the credibility of such models, are frequently raised. Following presentation of its components, a review of the application and reporting of model performance evaluation is presented. Taking cardiovascular disease as an illustrative example, the review investigates the use of face validity, internal validity, external validity, and cross model validity. As a part of the performance evaluation process, model calibration is also discussed and its use in applied studies investigated. The review found that the application and reporting of model performance evaluation across 81 studies of treatment for cardiovascular disease was variable. Cross-model validation was reported in 55 % of the reviewed studies, though the level of detail provided varied considerably. We found that very few studies documented other types of validity, and only 6 % of the reviewed articles reported a calibration process. Considering the above findings, we propose a comprehensive model performance evaluation framework (checklist), informed by a review of best-practice guidelines. This framework provides a basis for more accurate and consistent documentation of model performance evaluation. This will improve the peer review process and the comparability of modelling studies. Recognising the fundamental role of decision analytic models in informing public funding decisions, the proposed framework should usefully inform guidelines for preparing submissions to reimbursement bodies.

Cost-effectiveness analysis of rosuvastatin vs generic atorvastatin in Spain

OBJECTIVE

The objective of this study was to carry out a long-term cost-effectiveness analysis of rosuvastatin compared with generic atorvastatin in the treatment of patients at high cardiovascular (CV) risk (≥ 5% Systematic COronary Risk Evaluation [SCORE]) and patients with prior cardiovascular disease (CVD) in Spain.

METHODS

The efficacy data from the Statin Therapies for Elevated Lipid Levels compared Across doses to Rosuvastatin (STELLAR) study were used to simulate achievement of low-density lipoprotein cholesterol targets with different doses of rosuvastatin and generic atorvastatin for an initial period of 1 year. A Markov model was used to estimate the number of CV complications, quality-adjusted life years (QALYs), and healthcare costs (lipid-lowering treatment and CV events) for up to 20 years after initial treatment. The analysis was carried out from the perspective of the Spanish National Health System, with costs (in year 2010 euros) and effects being discounted at 3% per year.

RESULTS

Compared with generic atorvastatin, rosuvastatin was cost-effective (cost per QALY gained of less than €30,000) for the primary prevention of CV events in high-risk patients in most sub-groups analyzed. In patients with prior CVD, rosuvastatin was cost-effective in all sub-groups of men and most sub-groups of women. Key limitations of this study were the need to extrapolate data from a single trial to long-term modeled outcomes and the absence of other treatment options in the analysis.

CONCLUSIONS

For the treatment of dyslipidemic patients with high CV risk, rosuvastatin is more effective than generic atorvastatin in terms of survival and quality-of-life adjusted survival, with incremental cost-effectiveness ratios within the range generally used in Spain, in most sub-populations defined by various combinations of CV risk factors.

Cost effectiveness of fondaparinux in non-ST-elevation acute coronary syndrome

BACKGROUND

Fondaparinux has been shown to reduce the risk of major bleeding and 30-day mortality compared with enoxaparin, in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS). However, its cost effectiveness is not well known.

OBJECTIVE

To evaluate the effectiveness and economic attractiveness of fondaparinux relative to enoxaparin in patients with NSTE-ACS treated with triple antiplatelet therapy and early (non-urgent) invasive strategy.

METHODS

The decision model compares two alternative strategies: subcutaneous (SC) enoxaparin (1 mg/kg 12 hourly) versus SC fondaparinux (2.5 mg/day) in NSTE-ACS patients pre-treated with triple antiplatelet therapy and early revascularization. Cost-effectiveness and cost-utility analyses were performed from a healthcare perspective, based on a Markov model with a time horizon of the patient lifespan. Univariate sensitivity analysis and probabilistic (Monte Carlo) microsimulation analysis were performed.

RESULTS

In the base-case analysis (65 years, Thrombolysis In Myocardial Infarction [TIMI] score 4), the use of fondaparinux was associated with a significant reduction in major bleeding, a slight reduction in adverse cardiac events, and minor improvements in survival and QALYs, together with a small reduction in costs. The dominance of fondaparinux over enoxaparin remained unchanged in the univariate sensitivity analyses. According to Monte Carlo simulation, fondaparinux was cost saving in 99.9% of cases.

CONCLUSION

Compared with enoxaparin, the use of fondaparinux in patients with NSTE-ACS managed with an early invasive strategy appears to be cost effective, even in patients with a low risk of bleeding.