Results of a Markov model analysis to assess the cost-effectiveness of a single tablet of fixed-dose amlodipine and atorvastatin for the primary prevention of cardiovascular disease in Korea

Prevention of non-communicable disease: best buys, wasted buys, and contestable buys

Wanrudee Isaranuwatchai and colleagues highlight the importance of local context in making decisions about implementing interventions for preventing non-communicable diseases

Cost-Effectiveness Analysis of Ezetimibe as the Add-on Treatment to Moderate-Dose Rosuvastatin versus High-Dose Rosuvastatin in the Secondary Prevention of Cardiovascular Diseases in China: A Markov Model Analysis

BACKGROUND

For patients with inadequate control of cholesterol using moderate-dose statins in the secondary prevention of cardiovascular diseases (CVD), either doubling the dose of statins or adding ezetimibe should be considered. The cost-effectiveness of them is unknown in the Chinese context. The aim of this study is to compare the cost and effectiveness of the two regimens, and estimate the incremental cost-effectiveness ratio (ICER).

METHODS

A Markov model of five health statuses were used to estimate long-term costs and quality-adjusted life-years (QALYs) of the two treatment regimens from the healthcare perspective. The effectiveness data used to calculate the transition probability was based on a previously published randomized trial. The utility data was gathered from literature and the costs were gathered from the electronic medical record system of West China Hospital in Chinese Yuan (CNY) in 2017 price. One-way sensitivity analysis and probabilistic sensitivity analysis were conducted.

RESULTS

The ICER for ezetimibe plus moderate-dose rosuvastatin was 47,102.99 CNY per QALY for 20 years simulation, which did not reach the threshold of per capita gross domestic product (GDP) of 59,660 CNY per QALY in 2017 in China. Non-CVD-related mortality and CVD-related mortality contributed most to the ICER.

CONCLUSION

Adding ezetimibe to the moderate-dose statin in secondary prevention for CVD is cost-effective, compared with the high-dose statin in the Chinese context whose low-density lipoprotein cholesterol (LDL-c) was not inadequately controlled by moderate-dose statin alone.

A systematic literature review of methods of incorporating mortality in cost-effectiveness analyses of lipid-lowering therapies

AIMS

Cost effectiveness analysis (CEA) is a useful tool for estimating the value of an intervention in relation to alternatives. In cardiovascular disease (CVD), CEA is especially important, given the high economic and clinical burden. One key driver of value is CVD mortality prevention. However, data used to inform CEA parameters can be limited, given the difficulty in demonstrating statistically significant mortality benefit in randomized clinical trials (RCTs), due in part to the frequency of fatal events and limited trial durations. This systematic review identifies and summarizes whether published CVD-related CEAs have incorporated mortality benefits, and the methodology among those that did.

MATERIALS AND METHODS

A systematic literature review was conducted of CEAs of lipid-lowering therapies published between 2000-2017. Health technology assessments (HTA) and full-length manuscripts were included, and sources of mortality data and methods of applying mortality benefits were extracted. Results were summarized as proportions of articles to articulate common practices in CEAs of CVD.

RESULTS

This review identified 100 studies for inclusion, comprising 93 full-length manuscripts and seven HTA reviews. Among these, 99% assumed a mortality benefit in the model. However, 87 of these studies that incorporated mortality differences did so despite the trials used to inform model parameters not demonstrating statistically significant differences in mortality. None of the 12 studies that used statistically significant findings from an individual RCT were based on active control studies. In a sub-group analysis considering the 60 CEAs that incorporated a direct mortality benefit, 48 (80%) did not have RCT evidence for statistically significant benefit in CVD mortality.

LIMITATIONS AND CONCLUSIONS

The finding that few CEA models included mortality inputs from individual RCTs of lipid-lowering therapy may be surprising, as one might expect that treatment efficacy should be based on robust clinical evidence. However, regulatory requirements in CVD-related RCTs often lead to insufficient sample sizes and observation periods for detecting a difference in CVD mortality, which results in the use of intermediate outcomes, composite end-points, or meta-analysis to extrapolate long-term mortality benefit in a lifetime CEA.

Cost-Effectiveness Analysis of Screening for and Managing Identified Hypertension for Cardiovascular Disease Prevention in Vietnam

OBJECTIVE

To inform development of guidelines for hypertension management in Vietnam, we evaluated the cost-effectiveness of different strategies on screening for hypertension in preventing cardiovascular disease (CVD).

METHODS

A decision tree was combined with a Markov model to measure incremental cost-effectiveness of different approaches to hypertension screening. Values used as input parameters for the model were taken from different sources. Various screening intervals (one-off, annually, biannually) and starting ages to screen (35, 45 or 55 years) and coverage of treatment were analysed. We ran both a ten-year and a lifetime horizon. Input parameters for the models were extracted from local and regional data. Probabilistic sensitivity analysis was used to evaluate parameter uncertainty. A threshold of three times GDP per capita was applied.

RESULTS

Cost per quality adjusted life year (QALY) gained varied in different screening scenarios. In a ten-year horizon, the cost-effectiveness of screening for hypertension ranged from cost saving to Int$ 758,695 per QALY gained. For screening of men starting at 55 years, all screening scenarios gave a high probability of being cost-effective. For screening of females starting at 55 years, the probability of favourable cost-effectiveness was 90% with one-off screening. In a lifetime horizon, cost per QALY gained was lower than the threshold of Int$ 15,883 in all screening scenarios among males. Similar results were found in females when starting screening at 55 years. Starting screening in females at 45 years had a high probability of being cost-effective if screening biannually was combined with increasing coverage of treatment by 20% or even if sole biannual screening was considered.

CONCLUSION

From a health economic perspective, integrating screening for hypertension into routine medical examination and related coverage by health insurance could be recommended. Screening for hypertension has a high probability of being cost-effective in preventing CVD. An adequate screening strategy can best be selected based on age, sex and screening interval.

Fixed-dose combination therapy for the prevention of cardiovascular disease

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide, yet CVD risk factor control and secondary prevention rates remain low. A fixed-dose combination of blood pressure and cholesterol lowering and antiplatelet treatments into a single pill, or polypill, has been proposed as one strategy to reduce the global burden of CVD by up to 80% given its potential for better adherence and lower costs.

OBJECTIVES

To determine the effectiveness of fixed-dose combination therapy on reducing fatal and non-fatal CVD events and on improving blood pressure and lipid CVD risk factors for both primary and secondary prevention of CVD. We also aimed to determine discontinuation rates, adverse events, health-related quality of life, and costs of fixed-dose combination therapy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 6), MEDLINE Ovid (1946 to week 2 July 2013), EMBASE Ovid (1980 to Week 28 2013), ISI Web of Science (1970 to 19 July 2013), and the Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment Database (HTA), and Health Economics Evaluations Database (HEED) (2011, Issue 4) in The Cochrane Library. We used no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials of a fixed-dose combination therapy including at least one blood pressure lowering and one lipid lowering component versus usual care, placebo, or a single drug active component for any treatment duration in adults ≥ 18 years old with no restrictions on presence or absence of pre-existing cardiovascular disease.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected studies for inclusion and extracted the data. We evaluated risk of bias using the Cochrane risk of bias assessment tool. We sought to include outcome data on all-cause mortality, fatal and non-fatal CVD events, adverse events, changes in systolic and diastolic blood pressure, total and low density lipoprotein (LDL) cholesterol concentrations, discontinuation rates, quality of life, and costs. We calculated risk ratios (RR) for dichotomous data and weighted mean differences (MD) for continuous data with 95% confidence intervals (CI) using fixed-effect models when heterogeneity was low (I(2) < 50%) and random-effects models when heterogeneity was high (I(2) > 50%).

MAIN RESULTS

We found nine randomised controlled trials with a total of 7047 participants. Seven of the nine trials evaluated the effects of fixed-dose combination therapy on primary CVD prevention, and the trial length ranged from six weeks to 15 months. We found a moderate to high risk of bias in the domains of selection, performance, detection, attrition, and other types of bias in five of the nine trials. Compared with the comparator groups, the effects of the fixed-dose combination treatment on mortality (1.2% versus 1.0%, RR 1.26, 95% CI 0.67 to 2.38,  N = 3465) and cardiovascular events (4.0% versus 2.9%, RR 1.38, 95% CI 0.91 to 2.10, N = 2479) were uncertain (low quality evidence). The low event rates for these outcomes, limited availability of data as only two out of nine trials reported on these outcomes, and a high risk of bias in at least one domain suggest that these results should not be viewed with confidence. Adverse events were common in both the intervention (30%) and comparator (24%) groups, with participants randomised to fixed-dose combination therapy being 20% (95% CI 9% to 30%) more likely to report an adverse event. Notably, no serious adverse events were reported. Compared with placebo, the rate of discontinuation among participants randomised to fixed-dose combination was higher (14% versus 11%, RR 1.26 95% CI 1.02 to 1.55). The weighted mean differences in systolic and diastolic blood pressure between the intervention and control arms were -7.05 mmHg (95% CI -10.18 to -3.87) and -3.65 mmHg (95% CI -5.44 to -1.85), respectively. The weighted mean differences (95% CI) in total and LDL cholesterol between the intervention and control arms were -0.75 mmol/L (95% CI -1.05 to -0.46) and -0.81 mmol/L (95% CI -1.09 to -0.53), respectively. There was a high degree of statistical heterogeneity in comparisons of blood pressure and lipids (I(2) ≥ 70% for all) that could not be explained, so these results should be viewed with caution. Fixed-dose combination therapy improved adherence to a multi-drug strategy by 33% (26% to 41%) compared with usual care, but this comparison was reported in only one study. The effects of fixed-dose combination therapy on quality of life are uncertain, though these results were reported in only one trial. No trials reported costs.

AUTHORS' CONCLUSIONS

Compared with placebo, single drug active component, or usual care, the effects of fixed-dose combination therapy on all-cause mortality or CVD events are uncertain; only few trials report these outcomes and the included trials were primarily designed to observe changes in CVD risk factor levels rather than clinical events. Reductions in blood pressure and lipid parameters are generally lower than those previously projected, though substantial heterogeneity of results exists. Fixed-dose combination therapy is associated with modest increases in adverse events compared with placebo, single drug active component, or usual care but may be associated with improved adherence to a multidrug regimen. Ongoing trials of fixed-dose combination therapy will likely inform key outcomes.

The efficacy and tolerability of 'polypills': meta-analysis of randomised controlled trials

BACKGROUND

To assess the blood pressure and lipid-lowering efficacy and tolerability of 'polypills' used in cardiovascular disease prevention trials.

METHODOLOGY/PRINCIPAL FINDINGS

Systematic review and meta-analysis.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials, Medline, and PubMed databases were searched for eligible trials. Study inclusion criteria: Randomised controlled trials of at least six weeks duration, which compared a 'polypill' (that included at least one anti-hypertensive and one lipid-lowering medication) with a placebo (or one active component).

OUTCOME MEASURES

Change from baseline in systolic and diastolic blood pressures, and total and LDL-cholesterol; discontinuation of study medication and reported adverse effects. Of 44 potentially eligible studies, six trials (including 2,218 patients without previous cardiovascular disease) fulfilled the inclusion criteria. Compared with placebo, 'polypills' reduced systolic blood pressure by -9.2 mmHg (95% confidence interval (CI): -13.4, -5.0) diastolic blood pressure by -5.0 mmHg (95%CI: -7.4, -2.6), total cholesterol by -1.22 mmol/L (95%CI: -1.60, -0.84) and LDL-cholesterol by -1.02 mmol/L (95%CI: -1.37, -0.67). However, those taking a 'polypill' (vs. placebo or component) were more likely to discontinue medication (20% vs 14%) (Odds ratio: 1.5 (95% CI: 1.2, 1.9)). There was no significant difference in reported adverse effects amongst those on a 'polypill' (36% vs. 28%) (OR: 1.3 (95%CI: 0.7, 2.5)). There was high statistical heterogeneity in comparisons for blood pressure and lipid-lowering but use of random-effects and quality-effects models produced very similar results.

CONCLUSIONS/SIGNIFICANCE

Compared with placebo, the 'polypills' reduced blood pressure and lipids. Tolerability was lower amongst those on 'polypills' than those on placebo or one component, but differences were moderate. Effectiveness trials are needed to help clarify the status of 'polypills' in primary care and prevention strategies.

Value of primordial and primary prevention for cardiovascular disease: a policy statement from the American Heart Association

The process of atherosclerosis may begin in youth and continue for decades, leading to both nonfatal and fatal cardiovascular events, including myocardial infarction, stroke, and sudden death. With primordial and primary prevention, cardiovascular disease is largely preventable. Clinical trial evidence has shown convincingly that pharmacological treatment of risk factors can prevent events. The data are less definitive but also highly suggestive that appropriate public policy and lifestyle interventions aimed at eliminating tobacco use, limiting salt consumption, encouraging physical exercise, and improving diet can prevent events. There has been concern about whether efforts aimed at primordial and primary prevention provide value (ie, whether such interventions are worth what we pay for them). Although questions about the value of therapeutics for acute disease may be addressed by cost-effectiveness analysis, the long time frames involved in evaluating preventive interventions make cost-effectiveness analysis difficult and necessarily flawed. Nonetheless, cost-effectiveness analyses reviewed in this policy statement largely suggest that public policy, community efforts, and pharmacological intervention are all likely to be cost-effective and often cost saving compared with common benchmarks. The high direct medical care and indirect costs of cardiovascular disease-approaching $450 billion a year in 2010 and projected to rise to over $1 trillion a year by 2030-make this a critical medical and societal issue. Prevention of cardiovascular disease will also provide great value in developing a healthier, more productive society.