Cost-effectiveness of primary prevention of paediatric asthma: a decision-analytic model

BACKGROUND

Many children stand to benefit from being asthma-free for life with primary (i.e., prenatally started) prevention addressing one environmental exposure in a unifaceted (UF) approach or at least two in a multifaceted (MF) approach. We assessed the cost-effectiveness of primary prevention programmes for Dutch children in a decision-analytic framework.

METHODS

A decision-analytic tree model analysing healthcare costs and asthma cases prevented was developed to compare usual care (UC) with two UF and three MF programmes on the primary prevention of asthma amongst children. Programmes were evaluated through incremental cost-effectiveness ratios and net monetary benefits. Decision and parameter uncertainty were subjected to value-of-information analyses.

RESULTS

The current UC and one of three MF programmes dominated the other alternatives. The MF programme was more costly but also more effective than UC at an incremental cost-effectiveness ratio of <euro>8,209.20/additional asthma case prevented. The value of perfect information to reduce uncertainty was <euro>291.6M at its lowest. Most of the uncertainty in the cost-effectiveness threshold was attributable to the probability and cost estimates for low-risk children.

CONCLUSION

This study supports the feasibility of a structured programme that simultaneously addresses exposure to house dust mites, pet dander, environmental tobacco, and breast-feeding as a cost-effective alternative to UC in the primary prevention of asthma amongst children.

Optimizing the use of expert panel reference diagnoses in diagnostic studies of multidimensional syndromes

Background

In the absence of a gold standard, a panel of experts can be invited to assign a reference diagnosis for use in research. Available literature offers limited guidance on assembling and working with an expert panel for this purpose. We aimed to develop a protocol for an expert panel consensus diagnosis and evaluated its applicability in a pilot project.

Methods

An adjusted Delphi method was used, which started with the assessment of clinical vignettes by 3 experts individually, followed by a consensus discussion meeting to solve diagnostic discrepancies. A panel facilitator ensured that all experts were able to express their views, and encouraged the use of argumentation to arrive at a specific diagnosis, until consensus was reached by all experts. Eleven vignettes of patients suspected of having a primary neurodegenerative disease were presented to the experts. Clinical information was provided stepwise and included medical history, neurological, physical and cognitive function, brain MRI scan, and follow-up assessments over 2 years. After the consensus discussion meeting, the procedure was evaluated by the experts.

Results

The average degree of consensus for the reference diagnosis increased from 52% after individual assessment of the vignettes to 94% after the consensus discussion meeting. Average confidence in the diagnosis after individual assessment was 85%. This did not increase after the consensus discussion meeting. The process evaluation led to several recommendations for improvement of the protocol.

Conclusion

A protocol for attaining a reference diagnosis based on expert panel consensus was shown feasible in research practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-014-0190-3) contains supplementary material, which is available to authorized users.

Modelling outcomes of complex treatment strategies following a clinical guideline for treatment decisions in patients with rheumatoid arthritis

BACKGROUND

Management of rheumatoid arthritis (RA) is characterised by a sequence of disease-modifying antirheumatic drugs (DMARDs) and biological response modifiers (BRMs). In most of the Western countries, the drug sequences are determined based on disease activity and treatment history of the patients. A model for realistic patient outcomes should reflect the treatment pathways relevant for patients with specific characteristics.

OBJECTIVE

This study aimed at developing a model that could simulate long-term patient outcomes and cost effectiveness of treatment strategies with and without inclusion of BRMs following a clinical guideline for treatment decisions.

METHODS

Discrete event simulation taking into account patient characteristics and treatment history was used for model development. Treatment effect on disease activity, costs, health utilities and times to events were estimated using Dutch observational studies. Long-term progression of physical functioning was quantified using a linear mixed-effects model. Costs and health utilities were estimated using two-part models. The treatment strategy recommended by the Dutch Society for Rheumatology where both DMARDs and BRMs were available (Strategy 2) was compared with the treatment strategy without BRMs (Strategy 1). Ten thousand theoretical patients were tracked individually until death. In the probabilistic sensitivity analysis, Monte Carlo simulations were performed with 1,000 sets of parameters sampled from appropriate probability distributions.

RESULTS

The simulated changes over time in disease activity and physical functioning were plausible. The incremental cost per quality-adjusted life-year gained of Strategy 2 compared with Strategy 1 was <euro>124,011. At a willingness-to-pay threshold higher than <euro>119,167, Strategy 2 dominated Strategy 1 in terms of cost effectiveness but the probability that the Strategy 2 is cost effective never exceeded 0.87.

CONCLUSIONS

It is possible to model the outcomes of complex treatment strategies based on a clinical guideline for the management of RA. Following the Dutch guideline and using real-life data, inclusion of BRMs in the treatment strategy for RA appeared to be less favourable in our model than in most of the existing models that compared drug sequences independent of patient characteristics and used data from randomised controlled clinical trials. Despite complexity and demand for extensive data, our modelling approach can help to identify the knowledge gaps in clinical guidelines for RA management and priorities for future research.

Is it cost-effective to use a test to decide which individuals with an intermediate cardiovascular disease risk would benefit from statin treatment?

BACKGROUND

The 2012 European guidelines recommend statins for intermediate-risk individuals with elevated cholesterol levels. Improved discrimination of intermediate-risk individuals is needed to prevent both cardiovascular disease (CVD) and statin side-effects (e.g. myopathy) efficiently since only 3-15 in every 100 individuals actually experience a cardiovascular event in the next 10 years. We estimated the potential cost-effectiveness of a hypothetical test which helps to determine which individuals will benefit from statins.

METHODS AND RESULTS

Prognosis of different age- and gender-specific cohorts with an intermediate risk was simulated with a Markov model to estimate the potential costs and quality-adjusted life-years for four strategies: treat all with statins, treat none with statins, treat according to the European guidelines, or use a test to select individuals for statin treatment. The test-first strategy dominated the other strategies if the hypothetical test was 100% accurate and cost no more than €237. This strategy and the treat-all strategy were equally effective but the test generated lower costs by reducing statin usage and side-effects. The treat-none strategy was the least effective strategy. Threshold analyses show that the test must be highly accurate (especially sensitive) and inexpensive to be the most cost-effective strategy, since myopathy has a negligible impact on cost-effectiveness and statin costs are low.

CONCLUSION

Use of a highly accurate prognostic test could reduce overall CVD risk, frequency of drug side-effects and lifetime costs. However, no additional test would add usefully to risk prediction over SCORE when it does not satisfy the costs and accuracy requirements.

The long term effectiveness and cost-effectiveness of initiating treatment for ocular hypertension

PURPOSE

To investigate the long-term health and economic consequences of direct treatment initiation in ocular hypertension patients.

METHODS

A cost-effectiveness analysis with a societal perspective and a lifelong horizon was performed. The primary outcomes were the incremental quality-adjusted life years (QALYs) and costs of direct pressure-lowering treatment for ocular hypertension, compared to a strategy where treatment is postponed until conversion to glaucoma has been observed. We used a decision analytic model based on individual patient simulation to forecast disease progression and treatment decisions in both strategies in a representative heterogeneous patient population and in 18 patient subgroups stratified by initial intraocular pressure and additional risk factors for conversion.

RESULTS

The incremental discounted health gain of direct treatment was 0.27 QALYs, whereas the incremental discounted costs were -€ 649 during an average lifetime of 26 years. In the simulations of patient subgroups, the model outcomes moved towards higher health gains and lower incremental costs with increasing risk of conversion in the patient population. The incremental cost-effectiveness ratio of direct treatment ranged from € 15,425 per QALY gained in the lowest-risk subgroup to dominance in the highest-risk subgroup. Probabilistic sensitivity analysis indicated that uncertainty surrounding the model input parameters did not affect the conclusions.

CONCLUSION

Direct, early, pressure-lowering treatment is a dominant cost-effective treatment strategy over a strategy to start the same treatment approach later, after glaucoma has occurred for patients with ocular hypertension. Its implementation and consequences should be discussed with ophthalmologists and individual patients.

Consumer willingness to invest money and time for benefits of lifestyle behaviour change: an application of the contingent valuation method

OBJECTIVE

To use contingent valuation (CV) to derive individual consumer values for both health and broader benefits of a public-health intervention directed at lifestyle behaviour change (LBC) and to examine the feasibility and validity of the method.

METHOD

Participants of a lifestyle intervention trial (n = 515) were invited to complete an online CV survey. Respondents (n = 312) expressed willingness to invest money and time for changes in life expectancy, health-related quality of life (HRQOL) and broader quality of life aspects. Internal validity was tested for by exploring associations between explanatory variables (i.e. income, paid work, experience and risk factors for cardiovascular diseases) and willingness to invest, and by examining ordering effects and respondents' sensitivity to the scope of the benefits.

RESULTS

The majority of respondents (94.3%) attached value to benefits of LBC, and 87.4% were willing to invest both money and time. Respondents were willing to invest more for improvements in HRQOL (€42/month; 3 h/week) and broader quality of life aspects (€40/month; 2.6 h/week) than for improvements in life expectancy (€24/month; 2 h/week). Protest answers were limited (3%) and findings regarding internal validity were mixed.

CONCLUSION

The importance of broader quality of life outcomes to consumers suggests that these outcomes are relevant to be considered in the decision making. Our research showed that CV is a feasible method to value both health and broader outcomes of LBC, but generalizability to other areas of public health still needs to be examined. Mixed evidence regarding internal validity pleads for caution to use CV as only the base for decision making.

Preferences for potential innovations in non-invasive colorectal cancer screening: A labeled discrete choice experiment for a Dutch screening campaign

BACKGROUND

The introduction of innovative non-invasive screening tests (e.g. tests based on stool and blood samples or both) may be a solution to increase colorectal cancer (CRC) screening uptake. However, preferences for these non-invasive screening tests have not been investigated in great detail yet. The purpose of this article therefore is to elicit individuals' preferences for different non-invasive screening tests in a Dutch screening campaign context.

MATERIAL AND METHODS

We investigate preferences by means of a labeled discrete choice experiment. Data of 815 individuals, aged 55-75 years, are used in the analysis.

RESULTS

Multinomial logit model analysis showed that the combi-test is generally preferred over the blood-test and the (currently available) stool-test. Furthermore, besides the large effect of screening test type, there are significant differences in preference depending on participants' socio-demographic background. Finally, the analysis showed a significant positive effect on screening test choice for the attributes sensitivity, risk reduction, and level of evidence and a non-significant effect for the attribute unnecessary follow-up test.

CONCLUSION

Introducing new non-invasive screening tests that are based on a combination of stool and blood samples (or blood sample only) has the potential to increase CRC screening participation compared to the current standard stool-based test.

The effect of presenting information about invasive follow-up testing on individuals' noninvasive colorectal cancer screening participation decision: results from a discrete choice experiment

OBJECTIVES

Many national colorectal cancer screening campaigns have a similar structure. First, individuals are invited to take a noninvasive screening test, and, second, in the case of a positive screening test result, they are advised to undergo a more invasive follow-up test. The objective of this study was to investigate how much individuals' participation decision in noninvasive screening is affected by the presence or absence of detailed information about invasive follow-up testing and how this effect varies over screening tests.

METHODS

We used a labeled discrete choice experiment of three noninvasive colorectal cancer screening types with two versions that did or did not present respondents with detailed information about the possible invasive follow-up test (i.e., colonoscopy) and its procedure. We used data from 631 Dutch respondents aged 55 to 75 years. Each respondent received only one of the two versions (N = 310 for the invasive follow-up test information specification version, and N = 321 for the no-information specification version).

RESULTS

Mixed logit model results show that detailed information about the invasive follow-up test negatively affects screening participation decisions. This effect can be explained mainly by a decrease in choice shares for the most preferred screening test (a combined stool and blood sample test). Choice share simulations based on the discrete choice experiment indicated that presenting invasive follow-up test information decreases screening participation by 4.79%.

CONCLUSIONS

Detailed information about the invasive follow-up test has a negative effect on individuals' screening participation decisions in noninvasive colorectal cancer screening campaigns. This result poses new challenges for policymakers who aim not only to increase uptake but also to provide full disclosure to potential screening participants.

Challenges in modelling the cost effectiveness of various interventions for cardiovascular disease

OBJECTIVES

Decision analytic modelling is essential in performing cost-effectiveness analyses (CEAs) of interventions in cardiovascular disease (CVD). However, modelling inherently poses challenges that need to be dealt with since models always represent a simplification of reality. The aim of this study was to identify and explore the challenges in modelling CVD interventions.

METHODS

A document analysis was performed of 40 model-based CEAs of CVD interventions published in high-impact journals. We analysed the systematically selected papers to identify challenges per type of intervention (test, non-drug, drug, disease management programme, and public health intervention), and a questionnaire was sent to the corresponding authors to obtain a more thorough overview. Ideas for possible solutions for the challenges were based on the papers, responses, modelling guidelines, and other sources.

RESULTS

The systematic literature search identified 1,720 potentially relevant articles. Forty authors were identified after screening the most recent 294 papers. Besides the challenge of lack of data, the challenges encountered in the review suggest that it was difficult to obtain a sufficiently valid and accurate cost-effectiveness estimate, mainly due to lack of data or extrapolating from intermediate outcomes. Despite the low response rate of the questionnaire, it confirmed our results.

CONCLUSIONS

This combination of a review and a survey showed examples of CVD modelling challenges found in studies published in high-impact journals. Modelling guidelines do not provide sufficient guidance in resolving all challenges. Some of the reported challenges are specific to the type of intervention and disease, while some are independent of intervention and disease.

A reference case for economic evaluations in osteoarthritis: an expert consensus article from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO)

BACKGROUND

General recommendations for a reference case for economic studies in rheumatic diseases were published in 2002 in an initiative to improve the comparability of cost-effectiveness studies in the field. Since then, economic evaluations in osteoarthritis (OA) continue to show considerable heterogeneity in methodological approach.

OBJECTIVES

To develop a reference case specific for economic studies in OA, including the standard optimal care, with which to judge new pharmacologic and non-pharmacologic interventions.

METHODS

Four subgroups of an ESCEO expert working group on economic assessments (13 experts representing diverse aspects of clinical research and/or economic evaluations) were charged with producing lists of recommendations that would potentially improve the comparability of economic analyses in OA: outcome measures, comparators, costs and methodology. These proposals were discussed and refined during a face-to-face meeting in 2013. They are presented here in the format of the recommendations of the recently published Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement, so that an initiative on economic analysis methodology might be consolidated with an initiative on reporting standards.

RESULTS

Overall, three distinct reference cases are proposed, one for each hand, knee and hip OA; with diagnostic variations in the first two, giving rise to different treatment options: interphalangeal or thumb-based disease for hand OA and the presence or absence of joint malalignment for knee OA. A set of management strategies is proposed, which should be further evaluated to help establish a consensus on the "standard optimal care" in each proposed reference case. The recommendations on outcome measures, cost itemisation and methodological approaches are also provided.

CONCLUSIONS

The ESCEO group proposes a set of disease-specific recommendations on the conduct and reporting of economic evaluations in OA that could help the standardisation and comparability of studies that evaluate therapeutic strategies of OA in terms of costs and effectiveness.

High-sensitive troponin T assay for the diagnosis of acute myocardial infarction: an economic evaluation

Background

Delayed diagnosis and treatment of Acute Myocardial Infarction (AMI) has a major adverse impact on prognosis in terms of both morbidity and mortality. Since conventional cardiac Troponin assays have a low sensitivity for diagnosing AMI in the first hours after myocardial necrosis, high-sensitive assays have been developed. The aim of this study was to assess the cost effectiveness of a high-sensitive Troponin T assay (hsTnT), alone or combined with the heart-type fatty acid-binding protein (H-FABP) assay in comparison with the conventional cardiac Troponin (cTnT) assay for the diagnosis of AMI in patients presenting to the hospital with chest pain.

Methods

We performed a cost-utility analysis (quality adjusted life years-QALYs) and a cost effectiveness analysis (life years gained-LYGs) based on a decision analytic model, using a health care perspective in the Dutch context and a life time time-horizon. The robustness of model predictions was explored using one-way and probabilistic sensitivity analyses.

Results

For a life time incremental cost of 30.70 Euros, use of hsTnT over conventional cTnT results in gain of 0.006 Life Years and 0.004 QALY. It should be noted here that hsTnT is a diagnostic intervention which costs only 4.39 Euros/test more than the cTnT test. The ICER generated with the use of hsTnT based diagnostic strategy comparing with the use of a cTnT-based strategy, is 4945 Euros per LYG and 7370 Euros per QALY. The hsTnT strategy has the highest probability of being cost effective at thresholds between 8000 and 20000 Euros per QALY. The combination of hsTnT and h-FABP strategy’s probability of being cost effective remains lower than hsTnT at all willingness to pay thresholds.

Conclusion

Our analysis suggests that hsTnT assay is a very cost effective diagnostic tool relative to conventional TnT assay. Combination of hsTnT and H-FABP does not offer any additional economic and health benefit over hsTnT test alone.

Rapid fetal fibronectin testing to predict preterm birth in women with symptoms of premature labour: a systematic review and cost analysis

BACKGROUND

Premature birth is defined as birth of before 37 completed weeks' gestation. Not all pregnant women showing symptoms of preterm labour will go on to deliver before 37 weeks' gestation. Hence, addition of fetal fibronectin (fFN) testing to the diagnostic workup of women with suspected preterm labour may help to identify those women who do not require active management, and thus avoid unnecessary interventions, hospitalisations and associated costs.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of rapid fFN testing in predicting preterm birth (PTB) in symptomatic women.

DATA SOURCES

Bibliographic databases (including EMBASE, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials) were searched from 2000 to September/November 2011. Trial registers were also searched.

REVIEW METHODS

Systematic review methods followed published guidance; we assessed clinical effectiveness and updated a previous systematic review of test accuracy. Risk of bias was assessed using the Cochrane tool (randomised controlled trials; RCTs) and a modification of QUADAS-2 (diagnostic test accuracy studies; DTAs). Summary risk ratios or weighted mean difference were calculated using random-effects models. Summary sensitivity and specificity used a bivariate summary receiver operating characteristic model. Heterogeneity was investigated using subgroup and sensitivity analyses. Health economic analysis focused on cost consequences. The time horizon was hospital admission for observation. A main structural assumption was that, compared with usual care, fFN testing doesn't increase adverse events or negative pregnancy outcomes.

RESULTS

Five RCTs and 15 new DTAs were identified. No RCT reported significant effects of fFN testing on maternal or neonatal outcomes. One study reported a subgroup analysis of women with negative fFN test observed > 6 hours, which showed a reduction in length of hospital stay where results were known to clinicians. Combining data from new studies and the previous systematic review, the pooled estimates of sensitivity and specificity were: 76.7% and 82.7% for delivery within 7-10 days of testing; 69.1% and 84.4% for delivery < 34 weeks' gestation; and 60.8% and 82.3% for delivery < 37 weeks' gestation. Estimates were similar across all subgroups sensitivity analyses. The base-case cost analysis resulted in a cost saving of £23.87 for fFN testing compared with usual care. The fFN testing was cost-neutral at an approximate cost of £45. Probabilistic sensitivity analysis gave an incremental cost (saving) of -£25.59 (97.5% confidence interval -£304.96 to £240.06), indicating substantial uncertainty. Sensitivity analyses indicated that admission rate had the largest impact on results.

CONCLUSIONS

Fetal fibronectin testing has moderate accuracy for predicting PTB. The main potential role is likely to be reducing health-care resource usage by identifying women not requiring intervention. Evidence from RCTs suggests that fFN does not increase adverse outcomes and may reduce resource use. The base-case analysis showed a modest cost difference in favour of fFN testing, which is largely dependent on whether or not fFN testing reduces hospital admission. Currently, there are no high-quality studies and the existing trials were generally underpowered. Hence, there is a need for high-quality adequately powered trials using appropriate study designs to confirm the findings presented.

STUDY REGISTRATION

PROSPERO 2011:CRD42011001468. Available from www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42011001468.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

How to select the right cost-effectiveness model? : A systematic review and stepwise approach for selecting a transferable health economic evaluation model for rheumatoid arthritis

OBJECTIVE

In the current study, we propose an approach for selection of a model that is transferable to a specific decision-making context (in this case, the Netherlands), using the case of rheumatoid arthritis (RA). The objectives of this study were (a) to perform a systematic literature review to identify existing health economic evaluation models for economic evaluation of disease-modifying antirheumatic drugs (DMARDs) in RA; and (b) to test the appropriateness of a stepwise model-selection process.

METHODS

First, we searched Medline and Embase to identify relevant studies in the English language, published between 1 January 2002 and 31 August 2012. From the included studies, all unique models were identified. Second, we applied a multi-step approach to model selection. Models that did not meet all minimal methodological and structural requirements based on the Outcome Measures in Rheumatology (OMERACT) criteria were excluded. Next, models were assessed on the basis of their fit when transferred to the Dutch health care setting. The criteria for model fit were transferability factors, as published by Welte et al., after exclusion of those that were deemed transferable by simple adaptation. Finally, the remaining models underwent a general quality check using the Philips checklist. Models showing good fit and high quality were considered to be transferable to the Dutch health care setting, using simple adaptation.

RESULTS

The systematic literature search identified 498 articles, which included 33 unique health economic evaluation models. Only six models passed the minimal methodological and structural requirements. Two of these models had an imperfect transferability fit to the Dutch health care setting, according to the Welte method. The remaining four models were, according to the Philips method, of good quality and were expected to be transferable by a simple adaptation.

CONCLUSION

This study introduces a stepwise approach for selecting health economic evaluation models that are transferable by a simple adaptation. The approach seems feasible and can be applied in various therapeutic areas, provided that the minimal methodological and structural requirements are defined accordingly. Availability of health economic evaluation models coupled with structured model selection could improve the efficiency, quality and comparability of health economic research.

Natural progression model of cognition and physical functioning among people with mild cognitive impairment and alzheimer's disease

BACKGROUND

Empirical models of the natural history of Alzheimer's disease (AD) may help to evaluate new interventions for AD.

OBJECTIVE

We aimed to estimate AD-free survival time in people with mild cognitive impairment (MCI) and decline of cognitive and physical function in AD cases.

METHODS

Within the Kungsholmen project, 153 incident MCI and 323 incident AD cases (international criteria) were identified during 9 years of follow-up in a cognitively healthy cohort of elderly people aged ≥75 at baseline (n = 1,082). Global cognitive function was assessed with the Mini-Mental State Examination (MMSE), and daily life function was evaluated with the Katz index of activities of daily living (ADL) at each follow-up examination. Data were analyzed using parametric survival analysis and mixed effect models.

RESULTS

Median AD-free survival time of 153 participants with incident MCI was 3.5 years. Among 323 incident AD cases, the cognitive decline was 1.84 MMSE points per year, which was significantly associated with age. Physical functioning declined by 0.38 ADL points per year and was significantly associated with age, education, and MMSE, but not with gender.

CONCLUSION

Elderly people with MCI may develop AD in approximately 3.5 years. Both cognitive and physical function may decline gradually after AD onset. The empirical models can be used to evaluate long-term disease progression of new interventions for AD.

Screen or not to screen for peripheral arterial disease: guidance from a decision model

Background

Asymptomatic Peripheral Arterial Disease (PAD) is associated with greater risk of acute cardiovascular events. This study aims to determine the cost-effectiveness of one time only PAD screening using Ankle Brachial Index (ABI) test and subsequent anti platelet preventive treatment (low dose aspirin or clopidogrel) in individuals at high risk for acute cardiovascular events compared to no screening and no treatment using decision analytic modelling.

Methods

A probabilistic Markov model was developed to evaluate the life time cost-effectiveness of the strategy of selective PAD screening and consequent preventive treatment compared to no screening and no preventive treatment. The analysis was conducted from the Dutch societal perspective and to address decision uncertainty, probabilistic sensitivity analysis was performed. Results were based on average values of 1000 Monte Carlo simulations and using discount rates of 1.5% and 4% for effects and costs respectively. One way sensitivity analyses were performed to identify the two most influential model parameters affecting model outputs. Then, a two way sensitivity analysis was conducted for combinations of values tested for these two most influential parameters.

Results

For the PAD screening strategy, life years and quality adjusted life years gained were 21.79 and 15.66 respectively at a lifetime cost of 26,548 Euros. Compared to no screening and treatment (20.69 life years, 15.58 Quality Adjusted Life Years, 28,052 Euros), these results indicate that PAD screening and treatment is a dominant strategy. The cost effectiveness acceptability curves show 88% probability of PAD screening being cost effective at the Willingness To Pay (WTP) threshold of 40000 Euros. In a scenario analysis using clopidogrel as an alternative anti-platelet drug, PAD screening strategy remained dominant.

Conclusion

This decision analysis suggests that targeted ABI screening and consequent secondary prevention of cardiovascular events using low dose aspirin or clopidogrel in the identified patients is a cost-effective strategy. Implementation of targeted PAD screening and subsequent treatment in primary care practices and in public health programs is likely to improve the societal health and to save health care costs by reducing catastrophic cardiovascular events.

The impact of structural uncertainty on cost-effectiveness models for adjuvant endocrine breast cancer treatments: the need for disease-specific model standardization and improved guidance

INTRODUCTION

Structural uncertainty relates to differences in model structure and parameterization. For many published health economic analyses in oncology, substantial differences in model structure exist, leading to differences in analysis outcomes and potentially impacting decision-making processes. The objectives of this analysis were (1) to identify differences in model structure and parameterization for cost-effectiveness analyses (CEAs) comparing tamoxifen and anastrazole for adjuvant breast cancer (ABC) treatment; and (2) to quantify the impact of these differences on analysis outcome metrics.

METHODS

The analysis consisted of four steps: (1) review of the literature for identification of eligible CEAs; (2) definition and implementation of a base model structure, which included the core structural components for all identified CEAs; (3) definition and implementation of changes or additions in the base model structure or parameterization; and (4) quantification of the impact of changes in model structure or parameterizations on the analysis outcome metrics life-years gained (LYG), incremental costs (IC) and the incremental cost-effectiveness ratio (ICER).

RESULTS

Eleven CEA analyses comparing anastrazole and tamoxifen as ABC treatment were identified. The base model consisted of the following health states: (1) on treatment; (2) off treatment; (3) local recurrence; (4) metastatic disease; (5) death due to breast cancer; and (6) death due to other causes. The base model estimates of anastrazole versus tamoxifen for the LYG, IC and ICER were 0.263 years, €3,647 and €13,868/LYG, respectively. In the published models that were evaluated, differences in model structure included the addition of different recurrence health states, and associated transition rates were identified. Differences in parameterization were related to the incidences of recurrence, local recurrence to metastatic disease, and metastatic disease to death. The separate impact of these model components on the LYG ranged from 0.207 to 0.356 years, while incremental costs ranged from €3,490 to €3,714 and ICERs ranged from €9,804/LYG to €17,966/LYG. When we re-analyzed the published CEAs in our framework by including their respective model properties, the LYG ranged from 0.207 to 0.383 years, IC ranged from €3,556 to €3,731 and ICERs ranged from €9,683/LYG to €17,570/LYG.

CONCLUSION

Differences in model structure and parameterization lead to substantial differences in analysis outcome metrics. This analysis supports the need for more guidance regarding structural uncertainty and the use of standardized disease-specific models for health economic analyses of adjuvant endocrine breast cancer therapies. The developed approach in the current analysis could potentially serve as a template for further evaluations of structural uncertainty and development of disease-specific models.

A systematic review of model-based economic evaluations of diagnostic and therapeutic strategies for lower extremity artery disease

Lower extremity artery disease (LEAD) is a sign of wide spread atherosclerosis also affecting coronary, cerebral and renal arteries and is associated with increased risk of cardiovascular events. Many economic evaluations have been published for LEAD due to its clinical, social and economic importance. The aim of this systematic review was to assess modelling methods used in published economic evaluations in the field of LEAD. Our review appraised and compared the general characteristics, model structure and methodological quality of published models. Electronic databases MEDLINE and EMBASE were searched until February 2013 via OVID interface. Cochrane database of systematic reviews, Health Technology Assessment database hosted by National Institute for Health research and National Health Services Economic Evaluation Database (NHSEED) were also searched. The methodological quality of the included studies was assessed by using the Philips' checklist. Sixteen model-based economic evaluations were identified and included. Eleven models compared therapeutic health technologies; three models compared diagnostic tests and two models compared a combination of diagnostic and therapeutic options for LEAD. Results of this systematic review revealed an acceptable to low methodological quality of the included studies. Methodological diversity and insufficient information posed a challenge for valid comparison of the included studies. In conclusion, there is a need for transparent, methodologically comparable and scientifically credible model-based economic evaluations in the field of LEAD. Future modelling studies should include clinically and economically important cardiovascular outcomes to reflect the wider impact of LEAD on individual patients and on the society.

Cost for Treatment of Chronic Lymphocytic Leukemia in Specialized Institutions of Ukraine

OBJECTIVE

The aim of this study was to identify, from a health care perspective, the cost of treatment for chronic lymphocytic leukemia in specialized hospitals in Ukraine.

METHODS

Cost analysis was performed by using retrospective data between 2006 and 2010 from patient-file databases of two specialized hospitals (145 patients). Uncertainty was assessed by using bootstrapping and multivariate sensitivity analyses. Linear regression analysis was used to analyze whether patients' characteristics are related to health care costs. In addition, one-way analysis of variance (Welch test) and paired-sample t test were conducted to compare mean costs of treatment between the two hospitals and mean expenses for drugs and in-hospital stay.

RESULTS

The average annual cost for a patient's drug treatment is 2047 EUR. The cost of hospitalization was significantly lower (t = 5.026; significance two-tailed = 0.000) and equal to 541 EUR per person, resulting in total expenditures of 2589 EUR. Mean total costs in the bootstrap analysis were equal to 2584 EUR (median 2576 EUR, 97.5th percentile 3223 EUR; 2.5th percentile 1987 EUR). The regression analysis did not reveal a relation between patients' characteristics and health care costs, although hospital choice was an influential parameter (β = -0.260; significance = 0.002). Significant difference in mean costs of two analyzed hospitals was also confirmed by one-way analysis of variance (Welch statistics 19.222, P = 0.000).

CONCLUSIONS

Drug treatment comprises the largest portion of total costs, but differences between hospitals exist. Because many patients in Ukraine pay out of pocket for in-hospital drugs, these costs are a high economic burden for patients with chronic lymphocytic leukemia.

The cloudy crystal ball of cost-effectiveness studies

Despite the use of identical clinical trial data (Anastrazole, Tamoxifen, Alone or in Combination for the adjuvant treatment of postmenopausal women with localised hormone receptor-positive breast cancer data), not dependent on differences between countries, the outcome of 11 published cost-effectiveness analyses varied more than 20-fold. The observed wide variation in predicted life-years gained (a parameter derived from clinical trial data) demonstrates that authors used substantially different methods for handling the same data. We therefore consider it to be of utmost importance to strive for standardization of and better guidance for disease-specific modeling in economic evaluations.