Cornelis Boersma

Interpreting Indirect Treatment Comparisons and Network Meta-Analysis for Health-Care Decision Making: Report of the ISPOR Task Force on Indirect Treatment Comparisons Good Research Practices: Part 1

Evidence-based health-care decision making requires comparisons of all relevant competing interventions. In the absence of randomized, controlled trials involving a direct comparison of all treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for judiciously selecting the best choice(s) of treatment. Mixed treatment comparisons, a special case of network meta-analysis, combine direct and indirect evidence for particular pairwise comparisons, thereby synthesizing a greater share of the available evidence than a traditional meta-analysis. This report from the ISPOR Indirect Treatment Comparisons Good Research Practices Task Force provides guidance on the interpretation of indirect treatment comparisons and network meta-analysis to assist policymakers and health-care professionals in using its findings for decision making. We start with an overview of how networks of randomized, controlled trials allow multiple treatment comparisons of competing interventions. Next, an introduction to the synthesis of the available evidence with a focus on terminology, assumptions, validity, and statistical methods is provided, followed by advice on critically reviewing and interpreting an indirect treatment comparison or network meta-analysis to inform decision making. We finish with a discussion of what to do if there are no direct or indirect treatment comparisons of randomized, controlled trials possible and a health-care decision still needs to be made.

Conducting indirect-treatment-comparison and network-meta-analysis studies: Report of the ISPOR task force on indirect treatment comparisons good research practices: Part 2

Evidence-based health care decision making requires comparison of all relevant competing interventions. In the absence of randomized controlled trials involving a direct comparison of all treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for judiciously selecting the best treatment(s). Mixed treatment comparisons, a special case of network meta-analysis, combine direct evidence and indirect evidence for particular pairwise comparisons, thereby synthesizing a greater share of the available evidence than traditional meta-analysis. This report from the International Society for Pharmacoeconomics and Outcomes Research Indirect Treatment Comparisons Good Research Practices Task Force provides guidance on technical aspects of conducting network meta-analyses (our use of this term includes most methods that involve meta-analysis in the context of a network of evidence). We start with a discussion of strategies for developing networks of evidence. Next we briefly review assumptions of network meta-analysis. Then we focus on the statistical analysis of the data: objectives, models (fixed-effects and random-effects), frequentist versus Bayesian approaches, and model validation. A checklist highlights key components of network meta-analysis, and substantial examples illustrate indirect treatment comparisons (both frequentist and Bayesian approaches) and network meta-analysis. A further section discusses eight key areas for future research.

Pharmacoeconomic evaluations of pharmacogenetic and genomic screening programmes : A systematic review on content and adherence to guidelines

The fields of pharmacogenetics and pharmacogenomics have become important practical tools to progress goals in medical and pharmaceutical research and development. As more screening tests are being developed, with some already used in clinical practice, consideration of cost-effectiveness implications is important. A systematic review was performed on the content of and adherence to pharmacoeconomic guidelines of recent pharmacoeconomic analyses performed in the field of pharmacogenetics and pharmacogenomics.Economic analyses of screening strategies for genetic variations, which were evidence-based and assumed to be associated with drug efficacy or safety, were included in the review. The 20 papers included cover a variety of healthcare issues, including screening tests on several cytochrome P450 (CYP) enzyme genes, thiopurine S-methyltransferase (TMPT) and angiotensin-converting enzyme (ACE) insertion deletion (ACE I/D) polymorphisms.Most economic analyses reported that genetic screening was cost effective and often even clearly dominated existing non-screening strategies. However, we found a lack of standardization regarding aspects such as the perspective of the analysis, factors included in the sensitivity analysis and the applied discount rates. In particular, an important limitation of several studies related to the failure to provide a sufficient evidence-based rationale for an association between genotype and phenotype.Future economic analyses should be conducted utilizing correct methods, with adherence to guidelines and including extensive sensitivity analyses. Most importantly, genetic screening strategies should be based on good evidence-based rationales. For these goals, we provide a list of recommendations for good pharmacoeconomic practice deemed useful in the fields of pharmacogenetics and pharmacogenomics, regardless of country and origin of the economic analysis.

Quantification of the Potential Impact of Cost-effectiveness Thresholds on Dutch Drug Expenditures Using Retrospective Analysis

BACKGROUND Other than the UK, The Netherlands has no formal threshold for cost-per-QALY values defined yet. For example, a cutoff value at €20,000 per QALY is sometimes mentioned in various discussions, however it has no formal status at all. Yet, since 2005, all new innovative do have to go through a cost-effectiveness evaluation though, with the assessment being focused on the methodology rather than on the exact cost-per-QALY outcome. OBJECTIVE Our objective was to estimate the potential impacts on Dutch drug expenditures had a formal threshold been applied in recent years. METHODS We analyzed national Dutch prescription data for the period 2005-2007, with respect to the costs of specific newly introduced drugs with reported positive cost-effectiveness ratios. Various threshold values were investigated. RESULTS   In particular, our analysis suggests that modest, though annually increasing, reductions in Dutch drug expenditures could have been achieved in the recent period 2005-2007 if a threshold for cost-effectiveness at, for example, €20,000 per QALY been applied in The Netherlands. At thresholds of €0 and €20,000 estimated reductions in drug expenditures reflect approximately 0.25% of total Dutch drug expenditures and for thresholds of €50,000 and €80,000 this is only 0.01%. CONCLUSIONS Modest reductions in drug expenditures can be achieved if a formal threshold would be applied in The Netherlands. Potential reductions may be expected to increase in next years as expenditures for listed drugs increase further and new drugs become listed. Finally, we argue that for optimal and fair allocation of resources the in the health-care sector, application of a straightforward threshold is eminent and should not be postponed anymore.

Observed differences in invasive pneumococcal disease epidemiology after routine infant vaccination

Healthcare decisions on vaccination programs mainly rely on the direct burden of illness and related costs of the disease. Next to the expected direct beneficial effect of pediatric immunization programs against Streptococcus pneumoniae, worldwide implementation of these programs has also been driven by the indirect beneficial impact as observed among various nontargeted age groups in Northern America. In this article, we provide a descriptive overview of the post-marketing surveillance and show that there are large differences in the observed disease epidemiology after implementation of pediatric pneumococcal immunization programs across countries. Possible factors responsible for these differences may include vaccine-serotype coverage, implemented vaccination schedules, antibiotic resistance rates and pneumococcal disease incidence prior to vaccination. A potential limitation can be found in the installation or enhancement of existing surveillance systems as well as other potential confounding bias, which may have influenced observed disease rates in the included observational studies. We conclude that the health and economic impact should be addressed in light of the country specific pneumoccocal disease epidemiology to support decisions on immunization programs.

Economic Evaluations of Pharmacogenetic and Pharmacogenomic Screening Tests: A Systematic Review. Second Update of the Literature

Objective Due to extended application of pharmacogenetic and pharmacogenomic screening (PGx) tests it is important to assess whether they provide good value for money. This review provides an update of the literature. Methods A literature search was performed in PubMed and papers published between August 2010 and September 2014, investigating the cost-effectiveness of PGx screening tests, were included. Papers from 2000 until July 2010 were included via two previous systematic reviews. Studies’ overall quality was assessed with the Quality of Health Economic Studies (QHES) instrument. Results We found 38 studies, which combined with the previous 42 studies resulted in a total of 80 included studies. An average QHES score of 76 was found. Since 2010, more studies were funded by pharmaceutical companies. Most recent studies performed cost-utility analysis, univariate and probabilistic sensitivity analyses, and discussed limitations of their economic evaluations. Most studies indicated favorable cost-effectiveness. Majority of evaluations did not provide information regarding the intrinsic value of the PGx test. There were considerable differences in the costs for PGx testing. Reporting of the direction and magnitude of bias on the cost-effectiveness estimates as well as motivation for the chosen economic model and perspective were frequently missing. Conclusions Application of PGx tests was mostly found to be a cost-effective or cost-saving strategy. We found that only the minority of recent pharmacoeconomic evaluations assessed the intrinsic value of the PGx tests. There was an increase in the number of studies and in the reporting of quality associated characteristics. To improve future evaluations, scenario analysis including a broad range of PGx tests costs and equal costs of comparator drugs to assess the intrinsic value of the PGx tests, are recommended. In addition, robust clinical evidence regarding PGx tests’ efficacy remains of utmost importance.

Screen-and-treat strategies for albuminuria to prevent cardiovascular and renal disease: Cost-effectiveness of nationwide and targeted interventions based on analysis of cohort data from the Netherlands*

BACKGROUND Albuminuria is a marker for renal and cardiovascular (CV) risk, allowing early diagnosis of subjects with elevated renal and CV risk. OBJECTIVE This study aimed to estimate the cost-effectiveness and budget impact of various population-based screen-and-treat scenarios for elevated albuminuria levels (ie, microalbuminuria) in the Netherlands. METHODS A multistate transition Markov model was developed to simulate the natural course of albuminuria-based disease progression to dialysis and occurrence of CV events. Several population-based strategies directed at screening for elevated albuminuria were evaluated. These strategies depended on urinary albumin concentration (UAC), urinary albumin excretion (UAE), and age. Transition probabilities were derived from the observational community-based Prevention of Renal and Vascular End Stage Disease (PREVEND) cohort study. Health care costs (in year-2008 euros) and life-years gained were calculated over an 8-year period. In the base-case analysis, we analyzed screening for and treatment of microalbuminuria. Screening for microalbuminuria involved prescreening for UAC >or=20 mg/L, followed by a confirmation test for UAE >or=30 mg/d. Other options based on combinations of albuminuria for UAC prescreening (no prescreening, and >or=10, >or=20, >or=100, and >or=200 mg/L) and UAE confirmation test (>or=15, >or=30, and >or=300 mg/d) for treatment were investigated in scenario analyses. Furthermore, these various strategies based on UAC and UAE values were analyzed in different subgroups based on age (all ages, aged >or=50 years, and aged >or=60 years). RESULTS The PREVEND study included 8592 Dutch residents aged 28 to 75 years at the time of initial screening. Among a hypothetical cohort of 1000 subjects identified and treated in the base-case analysis, it was estimated (based on PREVEND follow-up data) that, in the screening/treatment and no-screening scenarios, 76 versus 124 CV events occurred, 16 versus 27 CV deaths, and 3 versus 5 dialysis cases, respectively. The per-person difference in net costs for screening was calculated at euro926 (euro2003 vs euro1077), and prevention of CV deaths was estimated to gain 0.0421 discounted life-year per person. Correspondingly, the cost-effectiveness was estimated at euro22,000 per life-year gained. In the base-case analysis, probabilistic sensitivity analysis indicated that the likelihood of cost-effectiveness of a screen-and-treat strategy was 54%, 90%, and 95% for a maximum acceptable cost-effectiveness threshold of euro20,000, euro50,000, and euro80,000 per life-year gained, respectively. Higher albuminuria thresholds for screening and start of treatment further improved the cost-effectiveness but reduced the overall health gains achieved. Limiting screening to those subjects aged >or=50 and >or=60 years resulted in more favorable cost-effectiveness compared with population-based screening without age restriction. CONCLUSIONS Our analyses suggest the potentially favorable cost-effectiveness of population-based screening for albuminuria in the general Dutch population. The results offer health care decision-makers new tools for considering actual implementation of such screening.

Economic evaluations of pharmacogenetic and genomic screening programs: update of the literature†

Pharmacogenetics and pharmacogenomics show great potential for developing individual treatment modalities to achieve optimal therapy effectiveness. Economic analyses are performed to determine whether pharmacogenetic screening strategies provide good value for money. The current review provides an update of published economic studies. Economic analyses of pharmacogenetic screening programs published between 2000 and July 2010 were included in the review. Information was extracted on research area, genetic information, type of economic analysis, key aspects of adherence to economic guidelines, costs and commercial availability of genetic tests, and the role of the funding party. A total of 42 economic studies on pharmacogenetic screening strategies were included. Over time, more cost‐utility analyses were performed, longer time windows were employed, and more extensive sensitivity analyses were conducted. Considerable differences in costs of screening tests for the same polymorphism were found, which often, but not always, had a large influence on the costs of screening strategies. Most studies were conducted from an academic or hospital perspective without direct links to pharmaceutical or diagnostic manufacturers. The quality of economic analyses of pharmacogenetic screening programs has improved over time. However, input variables are not always clearly described. In particular, substantial variation exists in the reported costs of the pharmacogenetic tests. Often these test costs are considered a major cost driver and could therefore be of particular importance for the interpretation of cost‐effectiveness results. Furthermore, the economic studies seem to be conducted to increase awareness of possibilities and perspectives of genetic testing rather than to influence policy decisions on reimbursement. Drug Dev Res 71: 492–501, 2010.  © 2010 Wiley‐Liss, Inc.

On discounting of health gains from human papillomavirus vaccination: Effects of different approaches

OBJECTIVES Discounting has long been a matter of controversy in the field of health economic evaluations. How to weigh future health effects has resulted in ongoing discussions. These discussions are imminently relevant for health care interventions with current costs but future benefits. Different approaches to discount health effects have been proposed. In this study, we estimated the impact of different approaches for discounting health benefits of human papillomavirus (HPV) vaccination. METHODS An HPV model was used to estimate the impact of different discounting approaches on the present value of health effects. For the constant discount approaches, we varied the discount rate for health effects ranging from 0% to 4%. Next, the impact of relevant alternative discounting approaches was estimated, including hyperbolic, proportional, stepwise, and time-shifted discounting. RESULTS The present value of health effects gained through HPV vaccination varied strongly when varying discount rates and approaches. The application of the current Dutch guidelines resulted in a present value of health effects that was eight or two times higher than that produced when using the proportional discounting approach or when using the internationally more common 4% discount rate for health effects, respectively. Obviously, such differences translate into large variations in corresponding incremental cost-effectiveness ratios. CONCLUSION The exact discount rate and approach chosen in an economic evaluation importantly impact the projected value of health benefits of HPV vaccination. Investigating alternative discounting approaches in health-economic analysis is important, especially for vaccination programs yielding health effects far into the future. Our study underlines the relevance of ongoing discussions on how and at what rates to discount.

Cost effectiveness of angiotensin receptor blocker monotherapy in patients with hypertension in the Netherlands: a comparative analysis using clinical trial and drug utilization data.

Background and ObjectiveHealth gains and related cost savings achieved by optimizing treatment in hypertensive patients is highly important. The aim of this study was to evaluate the costs and cost effectiveness of treatment with angiotensin II receptor antagonists (angiotensin II receptor blockers [ARBs]) in patients with essential hypertension and to compare within-trial with real-life dosing of ARBs.MethodsCost effectiveness was estimated based on a published clinical trial comparing the BP-lowering effects of olmesartan, losartan, valsartan, and irbesartan. BP lowering after 8 weeks of treatment was entered into the Framingham risk functions to estimate cardiovascular complications after 1 and 5 years, using an international health economics model that was adapted to the Netherlands. Dutch costs (2006 values) and complications derived from the model were discounted at 4% and 1.5%, respectively, and cost effectiveness was expressed in net costs per cardiovascular complication averted. In a drug-utilization study, pharmacy dispensing records were used to evaluate differences between within-trial and daily-practice dosing and related costs for treatment in the Netherlands.ResultsAfter 8 weeks, the trial-based analysis showed that treatment with olmesartan versus losartan, valsartan, and irbesartan resulted in a significantly larger decrease in BP (11.5 vs 8.2, 7.9 and 9.9 mmHg [p<0.05], respectively) and consequently more complications averted. Cost effectiveness for olmesartan, losartan, valsartan, and irbesartan was estimated at €39 100, €77 100, €70 700, and €50 900 per cardiovascular complication averted, respectively. The incremental cost-effectiveness analysis indicated the most favorable cost-effectiveness outcome for olmesartan, with lower costs and less cardiovascular complications for olmesartan compared with the other three ARBs. The drug-utilization analysis showed that the dosing followed within clinical trials was not found in daily practice. On average, losartan, valsartan, and irbesartan were administered at doses above those used in clinical trials, whereas olmesartan was dosed lower than in clinical trials, resulting in relatively lower costs.ConclusionBased on the exact trial data, olmesartan was estimated to be the most favorable option of the four ARBs based on within-trial decreases in BP levels after 8 weeks and in terms of cost-effectiveness for this particular Dutch setting. However, for definite conclusions to be drawn, this hypothesis-generating study requires confirmation from further prospective studies comparing ARBs based on comparable BP control and including hard endpoints.