Publications (45) View all
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Article: The Role of Value-of-Information Analysis in a Health Care Research Priority Setting: A Theoretical Case Study.
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ABSTRACT: BACKGROUND: The Dutch reimbursement procedure for expensive drugs requires the submission of a baseline cost-effectiveness (CE) analysis and a research plan for the period of temporary reimbursement to estimate the real-life cost-effectiveness after 4 years. The Dutch guidelines recommend a value-of-information analysis to identify the critical parameters to be studied in such an outcome study. OBJECTIVES: . Identify situations where sensitivity analyses are sufficient to establish the need for additional data collection and priority setting. METHODS: . We used a hypothetical Markov model with 3 groups of parameters. We performed deterministic and probabilistic sensitivity analyses (PSA) and analyzed the expected value of partial perfect information (EVPPI), for different configurations of input parameters and a range of threshold incremental cost-effectiveness ratios (λ). We introduced a multivariate (deterministic) sensitivity analysis and a partial PSA. RESULTS: . Deterministic, partial PSA, and EVPPI analyses came to the same ranking of priorities for future research in most cases, irrespective of the place of the results on the CE plane. Rankings differed only when the statistical metrics that we calculated for each method were close together. CONCLUSIONS: . When a clear ranking can be established, all methods lead to the same priority setting. If there is no clear ranking, we regard the parameters as equally important. Priority setting for future research depends on λ and the location of results on the CE plane. The EVPPI is needed to estimate the value of doing additional research, but to prioritize parameters for further research, extensive (partial probabilistic) sensitivity analyses and expected value of perfect information are often sufficient.Medical Decision Making 12/2012; · 2.33 Impact Factor -
Article: Cost-effectiveness of tiotropium versus salmeterol: the POET-COPD trial.
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ABSTRACT: The aim of this study was to perform a 1-year trial-based cost-effectiveness analysis (CEA) of tiotropium versus salmeterol followed by a 5-year model-based CEA.The within-trial CEA, including 7250 patients with moderate-to-very severe COPD, was performed alongside the 1-year international, randomized controlled POET-COPD trial comparing tiotropium with salmeterol regarding the effect on exacerbations. Main endpoints of the trial-based analysis were costs, number of exacerbations and exacerbation days. The model-based analysis was conducted to extrapolate results to 5 years and to calculate quality-adjusted life years (QALYs).One-year costs per patient from the German Statutory Health Insurance (SHI) perspective and the societal perspective were €126 (95% uncertainty interval (UI):55-195) and €170 (95% UI: 77-260) higher for tiotropium, respectively. The annual number of exacerbations was 0.064 (95% UI: 0.010-0.118) lower for tiotropium, leading to a reduction in exacerbation-related costs of €87 (95% UI: 19-157). The incremental cost-effectiveness ratio (ICER) was €1961 per exacerbation avoided from the SHI perspective and €2647 from the societal perspective. In the model-based analyses, the 5-year costs per QALY for the two perspectives were €3488 and €8141, respectively.Tiotropium reduced exacerbations and exacerbation-related costs, but increased total costs. The resulting cost-effectiveness ratios were below commonly accepted willingness-to-pay thresholds.European Respiratory Journal 06/2012; · 5.89 Impact Factor -
Article: Cost effectiveness of pharmacological maintenance treatment for chronic obstructive pulmonary disease: a review of the evidence and methodological issues.
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ABSTRACT: Over 200 million people have chronic obstructive pulmonary disease (COPD) worldwide. The number of disease-year equivalents and deaths attributable to COPD are high. Guidelines for the pharmacological treatment of the disease recommend an individualized step-up approach in which treatment is intensified when results are unsatisfactory. Our objective was to present a systematic review of the cost effectiveness of pharmacological maintenance treatment for COPD and to discuss the methodological strengths and weaknesses of the studies. A systematic literature search for economic evaluations of drug therapy in COPD was performed in MEDLINE, EMBASE, the Economic Evaluation Database of the UK NHS (NHS-EED) and the European Network of Health Economic Evaluation Databases (EURONHEED). Full economic evaluations presenting both costs and health outcomes were included. A total of 40 studies were included in the review. Of these, 16 were linked to a clinical trial, 14 used Markov models, eight were based on observational data and two used a different approach. The few studies on combining short-acting bronchodilators were consistent in finding net cost savings compared with monotherapy. Studies comparing inhaled corticosteroids (ICS) with placebo or no maintenance treatment reported inconsistent results. Studies comparing fluticasone with salmeterol consistently found salmeterol to be more cost effective. The cost-effectiveness studies of tiotropium versus placebo, ipratropium or salmeterol pointed towards a reduction in total COPD-related healthcare costs for tiotropium in many but not all studies. All of these studies reported additional health benefits of tiotropium. The cost-effectiveness studies of the combination of inhaled long-acting β₂-agonists and ICS all report additional health benefits at an increase in total COPD-related costs in most studies. The cost-per-QALY estimates of this combination treatment vary widely and are very sensitive to the assumptions on mortality benefit and time horizon. The currently available economic evaluations indicate differences in cost effectiveness between COPD maintenance therapies, but for a more meaningful comparison of results it is important to improve the consistency with respect to study methodology and choice of comparator.PharmacoEconomics 04/2012; 30(4):271-302. · 2.66 Impact Factor -
Article: Developing and applying a stochastic dynamic population model for chronic obstructive pulmonary disease.
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ABSTRACT: To develop a stochastic population model of disease progression in chronic obstructive pulmonary disease (COPD) that includes the effects of COPD exacerbations on health-related quality of life, costs, disease progression, and mortality and can be used to assess the effects of a wide range of interventions. The model is a multistate Markov model with time varying transition rates specified by age, sex, smoking status, COPD disease severity, and/or exacerbation type. The model simulates annual changes in COPD prevalence due to COPD incidence, exacerbations, disease progression (annual decline in the forced expiratory volume in 1 second as percentage of the predicted value), and mortality. The main outcome variables are quality-adjusted life years, total exacerbations, and COPD-related health care costs. Exacerbation-related input parameters were based on quantitative meta-analysis. All important model parameters are entered into the model as probability distributions. To illustrate the potential use of the model, costs and effects were calculated for 3-year implementation of three different COPD interventions, one pharmacologic, one on smoking cessation, and one on pulmonary rehabilitation using a time horizon of 10 years for reporting outcomes. Compared with minimal treatment the cost/quality-adjusted life year was €8,300 for the pharmacologic intervention, €10,800 for the smoking cessation therapy, €8,700 for the combination of the pharmacologic intervention and the smoking cessation therapy, and €17,200 for the pulmonary rehabilitation program. The probability of the interventions to be cost-effective at a ceiling ratio of €20,000 varied from 58% to 100%. The COPD model provides policy makers with information about the long-term costs and effects of interventions over the entire chain of care, from primary prevention to care for very severe COPD and includes uncertainty around the outcomes.Value in Health 12/2011; 14(8):1039-47. · 2.19 Impact Factor -
Article: Largely ignored: the impact of the threshold value for a QALY on the importance of a transferability factor.
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ABSTRACT: Recently, several checklists systematically assessed factors that affect the transferability of cost-effectiveness (CE) studies between jurisdictions. The role of the threshold value for a QALY has been given little consideration in these checklists, even though the importance of a factor as a cause of between country differences in CE depends on this threshold. In this paper, we study the impact of the willingness-to-pay (WTP) per QALY on the importance of transferability factors in the case of smoking cessation support (SCS). We investigated, for several values of the WTP, how differences between six countries affect the incremental net monetary benefit (INMB) of SCS. The investigated factors were demography, smoking prevalence, mortality, epidemiology and costs of smoking-related diseases, resource use and unit costs of SCS, utility weights and discount rates. We found that when the WTP decreased, factors that mainly affect health outcomes became less important and factors that mainly effect costs became more important. With a WTP below 1,000, the factors most responsible for between country differences in INMB were resource use and unit costs of SCS and the costs of smoking-related diseases. Utility values had little impact. At a threshold above 10,000, between country differences were primarily due to different discount rates, utility weights and epidemiology of smoking-related diseases. Costs of smoking-related diseases had little impact. At all thresholds, demography had little impact. We concluded that, when judging the transferability of a CE study, we should consider the between country differences in WTP threshold values.The European Journal of Health Economics 10/2011; 12(5):397-404. · 1.50 Impact Factor
