Assessing the appropriateness of combining economic data from multinational clinical trials

Costs of fall injuries in the STRIDE study: an economic evaluation of healthcare system heterogeneity and heterogeneity of treatment effect

OBJECTIVES

The Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE) Study cluster-randomized 86 primary care practices in 10 healthcare systems to a patient-centered multifactorial fall injury prevention intervention or enhanced usual care, enrolling 5451 participants. We estimated total healthcare costs from participant-reported fall injuries receiving medical attention (FIMA) that were averted by the STRIDE intervention and tested for healthcare-system-level heterogeneity and heterogeneity of treatment effect (HTE).

METHODS

Participants were community-dwelling adults age ≥ 70 at increased fall injury risk. We estimated practice-level total costs per person-year of follow-up (PYF), assigning unit costs to FIMA with and without an overnight hospital stay. Using independent variables for treatment arm, healthcare system, and their interaction, we fit a generalized linear model with log link, log follow-up time offset, and Tweedie error distribution.

RESULTS

Unadjusted total costs per PYF were $2,034 (intervention) and $2,289 (control). The adjusted (intervention minus control) cost difference per PYF was -$167 (95% confidence interval (CI), -$491, $216). Cost heterogeneity by healthcare system was present (p = 0.035), as well as HTE (p = 0.090). Adjusted total costs per PYF in control practices varied from $1,529 to $3,684 for individual healthcare systems; one system with mean intervention minus control costs of -$2092 (95% CI, -$3,686 to -$944) per PYF accounted for HTE, but not healthcare system cost heterogeneity.

CONCLUSIONS

We observed substantial heterogeneity of healthcare system costs in the STRIDE study, with small reductions in healthcare costs for FIMA in the STRIDE intervention accounted for by a single healthcare system.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT02475850).

Cost-effectiveness of palbociclib in early breast cancer patients with a high risk of relapse: Results from the PENELOPE-B trial

Background

Patients with hormone receptor-positive, HER2-negative breast cancer who have residual invasive disease after neoadjuvant chemotherapy (NACT) are at a high risk of relapse. PENELOPE-B was a double-blind, placebo-controlled, phase III trial that investigated adding palbociclib (PAL) for thirteen 28-day cycles to adjuvant endocrine therapy (ET) in these patients. Clinical results showed no significant improvement in invasive disease-free survival with PAL.

Methods

We performed a pre-planned cost-effectiveness analysis of PAL within PENELOPE-B from the perspective of the German statutory health insurance. Health-related quality of life scores, collected in the trial using the EQ-5D-3L instrument, were converted to utilities based on the German valuation algorithm. Resource use was valued using German price weights. Outcomes were discounted at 3% and modeled with mixed-level linear models to adjust for attrition, repeated measurements, and residual baseline imbalances. Subgroup analyses were performed for key prognostic risk factors. Scenario analyses addressed data limitations and evaluated the robustness of the estimated cost-effectiveness of PAL to methodological choices.

Results

The effects of PAL on quality-adjusted life years (QALYs) were marginal during the active treatment phase, increasing thereafter to 0.088 (95% confidence interval: −0.001; 0.177) QALYs gained over the 4 years of follow-up. The incremental costs were dominated by PAL averaging EUR 33,000 per patient; costs were higher in the PAL arm but not significantly different after the second year. At an incremental cost-effectiveness ratio of EUR 380,000 per QALY gained, PAL was not cost-effective compared to the standard-of-care ET. Analyses restricted to Germany and other subgroups were consistent with the main results. Findings were robust in the scenarios evaluated.

Conclusions

One year of PAL added to ET is not cost-effective in women with residual invasive disease after NACT in Germany.

Cost-effectiveness of a structured medication review approach for multimorbid older adults: Within-trial analysis of the OPERAM study

Background

Inappropriate polypharmacy has been linked with adverse outcomes in older, multimorbid adults. OPERAM is a European cluster-randomized trial aimed at testing the effect of a structured pharmacotherapy optimization intervention on preventable drug-related hospital admissions in multimorbid adults with polypharmacy aged 70 years or older. Clinical results of the trial showed a pattern of reduced drug-related hospital admissions, but without statistical significance. In this study we assessed the cost-effectiveness of the pharmacotherapy optimisation intervention.

Methods

We performed a pre-planned within-trial cost-effectiveness analysis (CEA) of the OPERAM intervention, from a healthcare system perspective. All data were collected within the trial apart from unit costs. QALYs were computed by applying the crosswalk German valuation algorithm to EQ-5D-5L-based quality of life data. Considering the clustered structure of the data and between-country heterogeneity, we applied Generalized Structural Equation Models (GSEMs) on a multiple imputed sample to estimate costs and QALYs. We also performed analyses by country and subgroup analyses by patient and morbidity characteristics.

Results

Trial-wide, the intervention was numerically dominant, with a potential cost-saving of CHF 3’588 (95% confidence interval (CI): -7’716; 540) and gain of 0.025 QALYs (CI: -0.002; 0.052) per patient. Robustness analyses confirmed the validity of the GSEM model. Subgroup analyses suggested stronger effects in people at higher risk.

Conclusion

We observed a pattern towards dominance, potentially resulting from an accumulation of multiple small positive intervention effects. Our methodological approaches may inform other CEAs of multi-country, cluster-randomized trials facing presence of missing values and heterogeneity between centres/countries.

Cost-effectiveness of budesonide/formoterol maintenance and rescue therapy in Thailand

Background: The prevalence of asthma has increased significantly in Thailand. Budesonide/formoterol maintenance and reliever therapy has been available for several years. However, cost-effectiveness of such treatment has never been examined in Thailand. Objective: Design a cost-effectiveness (CE) analysis conducted from a Thai healthcare perspective as a piggyback study accompanying a recent clinical trial. Methods: The CE analysis was conducted from the healthcare provider’s perspective. Data were collected from a six-month, double-blind, multi-national study involving 3321 symptomatic asthma patients randomized to either: bud/form maintenance and reliever therapy, bud/form 320/9 μg bid plus terbutaline as needed, or salmeterol/ fluticasone (salm/flut) 25/125 μg two inhalations bid plus terbutaline as needed. Efficacy was determined as the number of exacerbations per patient during a six-month period. Thai unit costs were collected from the national sources and expert opinions, and applied to the resource use data for a deterministic economic evaluation. Results: There were significantly fewer exacerbations in the bud/form maintenance and reliever therapy (0.12 events/patient/6 months) group vs. the bud/form (0.16 events/patient/6 months, p <0.01), or salm/flut groups (0.19 events/patient/6 months, p <0.001). Total direct costs (healthcare visits and drug costs) were 27.0% and 5.9% lower in the bud/form maintenance and reliever therapy group than in the bud/form and salm/flut groups, respectively. Conclusion: Bud/form maintenance and reliever therapy was associated with significantly fewer exacerbations, compared to other fixed combination treatments in a recent multi-national clinical trial. This might result in lower direct costs if applied to the Thai healthcare system.

[Economic analysis of multinational clinical trials in oncology]

In oncology, as in other fields of medicine, international multicentre clinical trials came into being so as to include a sufficient number of subjects to investigate a clinical situation. The existence of tight budgetary constraints and the desire to make the best use of the resources available have resulted in the development of economic evaluations associated with these trials, which, thanks to their level of evidence and their size, provide particularly relevant material. Nonetheless, economic evaluations alongside international clinical trials raise specific questions of methodology with regard to both the design and the analysis of the results. Indeed, the costs of goods and services consumed, the types and quantities of resources, and medical practices vary from one country to another and within an individual country. Economic data from the different countries involved must be available so as to study and to take into account this variability, and appropriate techniques for cost estimations and analysis must be implemented to aggregate the results from several countries. From a review of the literature, the aim of this work was to provide an overview of the specific methodological features of economic evaluations alongside international clinical trials: analysis of efficacy data from several countries, collection of resources and real costs, methods to establish the monetary value of resources, methods to aggregate results accounting for the trial effect.

High-dose inactivated influenza vaccine is associated with cost savings and better outcomes compared to standard-dose inactivated influenza vaccine in Canadian seniors

Seasonal influenza infects approximately 10–20% of Canadians each year, causing an estimated 12,200 hospitalizations and 3,500 deaths annually, mostly occurring in adults ≥65 years old (seniors). A 32,000-participant, randomized controlled clinical trial (FIM12; Clinicaltrials.gov NCT01427309) showed that high-dose inactivated influenza vaccine (IIV-HD) is superior to standard-dose vaccine (SD) in preventing laboratory-confirmed influenza illness in seniors. In this study, we performed a cost-utility analysis (CUA) of IIV-HD versus SD in FIM12 participants from a Canadian perspective. Healthcare resource utilization data collected in FIM12 included: medications, non-routine/urgent care and emergency room visits, and hospitalizations. Unit costs were applied using standard Canadian cost sources to estimate the mean direct medical and societal costs associated with each vaccine (2014 CAD). Clinical illness data from the trial were mapped to quality-of-life data from the literature to estimate differences in effectiveness between vaccines. Time horizon was one influenza season, however, quality-adjusted life-years (QALYs) lost due to death during the study were captured over a lifetime. A probabilistic sensitivity analysis (PSA) was also performed. Average per-participant medical costs were $47 lower and societal costs $60 lower in the IIV-HD arm. Hospitalizations contributed 91% of the total cost and were less frequent in the IIV-HD arm. IIV-HD provided a gain in QALYs and, due to cost savings, dominated SD in the CUA. The PSA indicated that IIV-HD is 89% likely to be cost saving. In Canada, IIV-HD is expected to be a less costly and more effective alternative to SD, driven by a reduction in hospitalizations.

Economic Evaluation alongside Multinational Studies: A Systematic Review of Empirical Studies

Purpose of the study

This study seeks to explore methods for conducting economic evaluations alongside multinational trials by conducting a systematic review of the methods used in practice and the challenges that are typically faced by the researchers who conducted the economic evaluations.

Methods

A review was conducted for the period 2002 to 2012, with potentially relevant articles identified by searching the Medline, Embase and NHS EED databases. Studies were included if they were full economic evaluations conducted alongside a multinational trial.

Results

A total of 44 studies out of a possible 2667 met the inclusion criteria. Methods used for the analyses varied between studies, indicating a lack of consensus on how economic evaluation alongside multinational studies should be carried out. The most common challenge appeared to be related to addressing differences between countries, which potentially hinders the generalisability and transferability of results. Other challenges reported included inadequate sample sizes and choosing cost-effectiveness thresholds.

Conclusions

It is recommended that additional guidelines be developed to aid researchers in this area and that these be based on an understanding of the challenges associated with multinational trials and the strengths and limitations of alternative approaches. Guidelines should focus on ensuring that results will aid decision makers in their individual countries.

Cost-effectiveness analysis alongside clinical trials II-An ISPOR Good Research Practices Task Force report

Clinical trials evaluating medicines, medical devices, and procedures now commonly assess the economic value of these interventions. The growing number of prospective clinical/economic trials reflects both widespread interest in economic information for new technologies and the regulatory and reimbursement requirements of many countries that now consider evidence of economic value along with clinical efficacy. As decision makers increasingly demand evidence of economic value for health care interventions, conducting high-quality economic analyses alongside clinical studies is desirable because they broaden the scope of information available on a particular intervention, and can efficiently provide timely information with high internal and, when designed and analyzed properly, reasonable external validity. In 2005, ISPOR published the Good Research Practices for Cost-Effectiveness Analysis Alongside Clinical Trials: The ISPOR RCT-CEA Task Force report. ISPOR initiated an update of the report in 2014 to include the methodological developments over the last 9 years. This report provides updated recommendations reflecting advances in several areas related to trial design, selecting data elements, database design and management, analysis, and reporting of results. Task force members note that trials should be designed to evaluate effectiveness (rather than efficacy) when possible, should include clinical outcome measures, and should obtain health resource use and health state utilities directly from study subjects. Collection of economic data should be fully integrated into the study. An incremental analysis should be conducted with an intention-to-treat approach, complemented by relevant subgroup analyses. Uncertainty should be characterized. Articles should adhere to established standards for reporting results of cost-effectiveness analyses. Economic studies alongside trials are complementary to other evaluations (e.g., modeling studies) as information for decision makers who consider evidence of economic value along with clinical efficacy when making resource allocation decisions.

Incorporating external evidence in trial-based cost-effectiveness analyses: the use of resampling methods

Background

Cost-effectiveness analyses (CEAs) that use patient-specific data from a randomized controlled trial (RCT) are popular, yet such CEAs are criticized because they neglect to incorporate evidence external to the trial. A popular method for quantifying uncertainty in a RCT-based CEA is the bootstrap. The objective of the present study was to further expand the bootstrap method of RCT-based CEA for the incorporation of external evidence.

Methods

We utilize the Bayesian interpretation of the bootstrap and derive the distribution for the cost and effectiveness outcomes after observing the current RCT data and the external evidence. We propose simple modifications of the bootstrap for sampling from such posterior distributions.

Results

In a proof-of-concept case study, we use data from a clinical trial and incorporate external evidence on the effect size of treatments to illustrate the method in action. Compared to the parametric models of evidence synthesis, the proposed approach requires fewer distributional assumptions, does not require explicit modeling of the relation between external evidence and outcomes of interest, and is generally easier to implement. A drawback of this approach is potential computational inefficiency compared to the parametric Bayesian methods.

Conclusions

The bootstrap method of RCT-based CEA can be extended to incorporate external evidence, while preserving its appealing features such as no requirement for parametric modeling of cost and effectiveness outcomes.

The road not taken: transferability issues in multinational trials

BACKGROUND

National regulatory agencies often have to use cost-effectiveness (CE) data from multinational randomized controlled trials (RCTs) for national decision making on reimbursement of new drugs. We need to make the best use of these patient-level data to obtain estimates of country-specific CE. Several methods, ranging from simple to statistically complex, have existed for years. We investigated which of these methods are used to estimate CE ratios in economic evaluations performed alongside recent, multinational RCTs that enrolled at least 500 patients.

METHODS

In this systematic literature review, studies were classified based on whether resource use, unit costs, health outcomes and utility value sets were obtained from all countries, a subset of countries or one country. We recorded if the study presented trial-wide and country-specific CE results and reported the statistical analyses that were used to estimate them.

RESULTS

We included 21 studies, of which the majority used measurements of health care utilization and health outcomes from all countries to estimate CE. Thirteen studies used a one-country valuation of health care utilization; six used a multi-country valuation. Despite the availability of country-specific utility value sets, none of the studies that presented quality-adjusted life-years (QALYs) used multi-country valuation. Valuation of health care utilization and health outcomes was not always consistent within a study: three studies combined a multi-country valuation of health care utilization, with a one-country valuation of health outcomes. Most studies calculated trial-wide CE estimates, while 11 studies calculated country- or region-specific estimates. Thirteen studies used relatively simple methods, which do not take the possible interaction between the country and treatment effect on health care utilization and health outcomes into account. Eight studies used more advanced statistical methods. Three of them used a fixed-effects modeling approach. Five studies explicitly took the hierarchical structure of the data into account, which leads to more appropriate estimates of population average results and associated standard errors. In this way, they help improve transferability of the published results.

CONCLUSION

Based on this systematic review, we concluded that the uptake of more advanced statistical methods has been relatively slow, while simpler naïve methods are still routinely employed.

Resource use and costs of treating acute cough/lower respiratory tract infections in 13 European countries: results and challenges

The objectives of this study were to estimate the resource use and cost of treating acute cough/lower respiratory tract infection (acute cough/LRTI) in 13 European countries, to explore reasons for differences in cost and to document the challenges that researchers face when collecting information on cost alongside multinational studies. Data on resource use and cost were collected alongside an observational study in 14 primary care networks across 13 European countries and a mean cost was generated for each network. The results show that the mean cost (standard deviation) of treating acute cough/LRTI in Europe ranged from euro23.88 (34.67) in Balatonfüred (Hungary) to euro116.47 (34.29) in Jonkoping (Sweden). The observed differences in costs were statistically significant (P < 0.01). Major cost drivers include general practitioner visits and drug costs in all networks, whilst differences in health systems and regional factors could account for differences in cost between networks. The major barrier to conducting multinational cost studies are barriers associated with identifying cost information.

Cost effectiveness of intensive lipid-lowering treatment for patients with congestive heart failure and coronary heart disease in the US

BACKGROUND

A recent study found fewer hospitalizations for congestive heart failure (CHF) patients receiving high-dose versus low-dose statin therapy.

OBJECTIVE

To examine the cost effectiveness of high-dose versus low-dose statin therapy in CHF patients.

METHODS

Two scenarios (literature-based [base-case scenario] vs trial-based post-event mortality [alternative scenario]) assessed the cost effectiveness of atorvastatin 80 mg/day (A80) versus atorvastatin 10 mg/day (A10) in patients with both CHF and coronary heart disease (CHD) [CHF/CHD], using a lifetime Markov model. The model predicts treatment-specific probabilities of major and minor cardiovascular events and death, based on clinical trial data. The quality of life and costs were literature based. Measures included costs per life-year saved (LYS) and QALY gained. Health consequences and costs were discounted at 3.0% annually. Analyses were conducted from the payer perspective and valued in $US, year 2006-7 values.

RESULTS

Literature-based mortality estimates (base case) increased life-years and QALYs for A80 compared with A10 (incremental cost-effectiveness ratios [ICERs]: $US9600 per LYS; $US13 600 per QALY). At a willingness to pay of $US100 000 per QALY, A80 was cost effective in 80% of simulations. A10 dominated A80 when using trial-based mortality estimates (alternative scenario). At a willingness to pay of $US100 000 per QALY, A80 was cost effective in 48% of simulations.

CONCLUSIONS

Intensive A80 treatment may be cost effective versus A10 in cardiovascular prevention in CHF/CHD patients in the US, due to projected gains in life expectancy and health-related quality of life. However, the results are highly sensitive to assumptions about the mortality rate in the model. When using the mortality rate observed in the trial, A10 dominates A80.

The analysis of multinational cost-effectiveness data for reimbursement decisions: a critical appraisal of recent methodological developments

Evidence produced by multinational trial-based cost-effectiveness studies is often used to inform decisions concerning the adoption of new healthcare technologies. A key issue relating to the use of this type of evidence is the extent to which trial-wide economic results are applicable to every single country participating in the study. We consider what role cost-effectiveness analysis alongside multinational trials should have in assisting reimbursement decisions at jurisdiction and national levels. Using the proposed framework as a benchmark to evaluate their relative pros and cons, we then describe and review the statistical approaches used in the multinational trial-based cost-effectiveness literature. The results of the review are used to define the desirable characteristics a statistical method for the analysis of data collected from different jurisdictions should have in order to be consistent with the proposed framework. It is argued that Bayesian hierarchical models that use both patient- and country-level information are the most appropriate tool to analyse multinational trial-based cost-effectiveness data and facilitate the between-country generalizability assessment of the study findings. The merits of each approach are discussed, highlighting problems and limitations, in order to identify areas of future research.

Cost effectiveness of enoxaparin in acute ST-segment elevation myocardial infarction: the ExTRACT-TIMI 25 (Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction 25) study

OBJECTIVES

We used a U.S. model of health care costs to examine the cost effectiveness of enoxaparin compared with unfractionated heparin (UFH) as adjunctive therapy for fibrinolysis in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

The ExTRACT-TIMI 25 (Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction 25) study, a large, randomized, multinational trial, demonstrated a reduction in death or nonfatal myocardial infarction when enoxaparin was used instead of UFH as adjunctive therapy for fibrinolysis in patients with STEMI.

METHODS

We used patient-level clinical outcomes and resource use from the ExTRACT-TIMI 25 trial and estimates of life expectancy gains as a result of the prevention of the clinical events on the basis of the Framingham Heart Study.

RESULTS

Index hospitalization costs trended lower by $126 in the enoxaparin group (95% confidence interval [CI]: -$295 to $49). Thirty-day costs trended higher by $102 for enoxaparin (95% CI: $108 to $314). Patients receiving enoxaparin gained an average of 0.12 life-years relative to patients given UFH. Estimated total lifetime costs were $1,207 higher in the enoxaparin group (95% CI: $491 to $1,923). The incremental cost-effectiveness ratio of enoxaparin compared with UFH was $5,700 per life-year gained, with 99.9% of bootstrap-derived estimates <$50,000 per life-year gained. Using a probabilistic sensitivity analysis, there is a 90% probability that enoxaparin is cost effective for lifetime, provided that the willingness-to-pay value exceeds $50,000.

CONCLUSIONS

Based on a U.S. model of health care economics, the strategy of using enoxaparin instead of UFH as adjunctive therapy for fibrinolysis in patients with STEMI is cost effective according to commonly used benchmarks.

The ISPOR Good Practices for Quality Improvement of Cost-Effectiveness Research Task Force Report

OBJECTIVES

The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Health Science Policy Council recommended and the ISPOR Board of Directors approved the formation of a Task Force to critically examine the major issues related to Quality Improvement in Cost-effectiveness Research (QICER). The Council's primary recommendation for this Task Force was that it should report on the quality of cost-effectiveness research and make recommendations to facilitate the improvement of pharmacoeconomics and health outcomes research and its use in stimulating better health care and policy. Task force members were knowledgeable and experienced in medicine, pharmacy, biostatistics, health policy and health-care decision-making, biomedical knowledge transfer, health economics, and pharmacoeconomics. They were drawn from industry, academia, consulting organizations, and advisors to governments and came from Japan, the Netherlands, Canada and the United States.

METHODS

Face-to-face meetings of the Task Force were held at ISPOR North American and European meetings and teleconferences occurred every few months. Literature reviews and surveys were conducted and the first preliminary findings presented at an open forum at the May 2008 ISPOR meeting in Toronto. The final draft report was circulated to the expert reviewer group and then to the entire membership for comment. The draft report was posted on the ISPOR Web site in April 2009. All formal comments received were posted to the association Web site and presented for discussion at the Task Force forum during the ISPOR 14th Annual International Meeting in May 2009. Comments and feedback from the forums, reviewers and membership were considered in the final report. Once Task Force consensus was reached, the article was submitted to Value in Health.

CONCLUSIONS

The QICER Task Force recommends that ISPOR implement the following: * With respect to CER guidelines, that ISPOR promote harmonization of guidelines, allowing for differences in application, regional needs and politics; evaluate available instruments or promote development of a new one that will allow standardized quantification of the impact of CER guidelines on the quality of CER studies; report periodically on those countries or regions that have developed guidelines; periodically evaluate the quality of published studies (those journals with CER guidances) or those submitted to decision-making bodies (as public transparency increases). * With respect to methodologies, that ISPOR promote publication of methodological guidelines in more applied journals in more easily understandable format to transfer knowledge to researchers who need to apply more rigorous methods; promote full availability of models in electronic format to combat space restrictions in hardcopy publications; promote consistency of methodological review for all CER studies; promote adoption of explicit best practices guidelines among regulatory and reimbursement authorities; periodically update all ISPOR Task Force reports; periodically review use of ISPOR Task Force guidelines; periodically report on statistical and methodological challenges in HE; evaluate periodically whether ISPOR's methodological guidelines lead to improved quality; and support training and knowledge transfer of rigorous CER methodologies to researchers and health care decision-makers. * With respect to publications, that ISPOR develop standard CER guidances to which journals will be able to refer their authors and their reviewers; lobby to establish these guidances within the International Committee for Medical Journal Editors (ICMJE) Requirements to which most journals refer in their Author Instructions; provide support in terms of additional reviewer expertise to those journals lacking appropriate reviewers; periodically report on journals publishing CER research; periodically report on the quality of CER publications; and support training and knowledge transfer of the use of these guidelines to researchers and reviewers. * With respect to evidence-based health-care decision-making, that ISPOR recognize at its annual meetings those countries/agencies/private companies/researchers using CER well, and those practitioners and researchers supporting good patient use of CER in decision-making; and promote public presentation of case studies of applied use of CER concepts or guidelines.

Prospective cost-effectiveness analysis of cetuximab in metastatic colorectal cancer: evaluation of National Cancer Institute of Canada Clinical Trials Group CO.17 trial

BACKGROUND

The National Cancer Institute of Canada Clinical Trials Group CO.17 study showed that patients with advanced colorectal cancer had improved overall survival when cetuximab, an epidermal growth factor receptor-targeting antibody, was given in addition to best supportive care. We conducted a cost-effectiveness analysis using prospectively collected resource utilization and health utility data for patients in the CO.17 study who received cetuximab plus best supportive care (N = 283) or best supportive care alone (N = 274).

METHODS

Direct medical resource utilization data were collected, including medications, physician visits, toxicity management, blood products, emergency department visits, and hospitalizations. Mean survival times for the study arms were calculated for the entire population and for the subset of patients with wild-type KRAS tumors over an 18- to 19-month period. All costs were presented in 2007 Canadian dollars. One-way and probabilistic sensitivity analysis was used to determine the robustness of the results. Cost-effectiveness acceptability curves were determined. The 95% confidence intervals (CIs) for the incremental cost-effectiveness ratios and the incremental cost-utility ratios were estimated by use of a nonparametric bootstrapping method (with 1000 iterations).

RESULTS

For the entire study population, the mean improvement in overall and quality-adjusted survival with cetuximab was 0.12 years and 0.08 quality-adjusted life-years (QALYs), respectively. The incremental cost with cetuximab compared with best supportive care was $23,969. The incremental cost-effectiveness ratio was $199,742 per life-year gained (95% CI = $125,973 to $652,492 per life-year gained) and the incremental cost-utility ratio was $299,613 per QALY gained (95% CI = $187,440 to $898,201 per QALY gained). For patients with wild-type KRAS tumors, the incremental cost with cetuximab was $33,617 and mean gains in overall and quality-adjusted survival were 0.28 years and 0.18 QALYs, respectively. The incremental cost-effectiveness ratio was $120,061 per life-year gained (95% CI = $88,679 to $207,075 per life-year gained) and the incremental cost-utility ratio was $186,761 per QALY gained (95% CI = $130,326 to $334,940 per QALY gained). In a sensitivity analysis, cetuximab cost and patient survival were the only variables that influenced cost-effectiveness.

CONCLUSIONS

The incremental cost-effectiveness ratio of cetuximab over best supportive care alone in unselected advanced colorectal cancer patients is high and sensitive to drug cost. Incremental cost-effectiveness ratios were lower when the analysis was limited to patients with wild-type KRAS tumors.

Cost-effectiveness of intensive atorvastatin therapy in secondary cardiovascular prevention in the United Kingdom, Spain, and Germany, based on the Treating to New Targets study

The Treating to New Targets (TNT) clinical trial found that intensive 80 mg atorvastatin (A80) treatment reduced cardiovascular events by 22% when compared to 10 mg atorvastatin (A10) treatment. We evaluated the cost-effectiveness of intensive A80 vs A10 treatment in the United Kingdom (UK), Spain, and Germany. A lifetime Markov model was developed to predict cardiovascular disease-related events, costs, survival, and quality-adjusted life-years (QALYs). Treatment-specific event probabilities were estimated from the TNT clinical trial. Post-event survival, health-related quality of life, and country-specific medical-care costs were estimated using published sources. Intensive treatment with A80 increased both the per-patient QALYs and corresponding costs of care, when compared to the A10 treatment, in all three countries. The incremental cost per QALY gained was <euro> 9,500, <euro> 21,000, and <euro> 15,000 in the UK, Spain, and Germany, respectively. Intensive A80 treatment is estimated to be cost-effective when compared to A10 treatment in secondary cardiovascular prevention.

Assessment of transparency of cost estimates in economic evaluations of patient safety programmes

OBJECTIVES

Transparency of costing is essential for decision-makers who require information on the efficiency of a health care programme, because effective decisions depend largely on applicability to their settings. The main objectives of this study were to assess published studies for transparency of cost estimates.

METHODS

We first developed criteria with two axes by reviewing publications dealing with economic evaluations and cost accounting studies: clarification of the scope of costing and accuracy of method evaluating costs. We then performed systematic searches of the literature for studies which estimated prevention costs and assessed the transparency and accuracy of costing based on our criteria.

RESULTS

Forty studies met the inclusion criteria. Half of the studies reported data for both the quantity and unit price of programmes in regard to prevention costs. Although 30 studies estimated costs of adverse events, 19 of these described the scope of costing only, and just five studies used a micro-costing method. Among 30 studies that estimated 'gross cost savings' and 'net cost savings', there was a huge discrepancy in labels.

CONCLUSIONS

Even if a cost study was conducted in accordance with existing techniques of economic evaluation which mostly paid attention to internal validity of cost estimates, without adequate explanation of the process of costing, reproducibility cannot be assured and the study may lose its value as scientific information. This study found that there is tremendous room for improvement.

Transferability indices for health economic evaluations: methods and applications

In this paper, we have elaborated an index in two phases to measure the degree of transferability of the results of the economic evaluation of health technologies. In the first phase, we have considered the objective factors (critical and non-critical) to derive a general transferability index, which can be used to measure this internal property of the studies of economic evaluation applied to health technologies. In the second phase, with a more specific index, we have measured the degree of applicability of the results of a given study to a different setting. Both indices have been combined (arithmetic and geometric mean) to obtain a global transferability index. We have applied the global index to a sample of 27 Spanish studies on infectious diseases. We have obtained an average value for the index of 0.54, quite far from the maximum theoretical value of 1. We also found that 11 studies lacked some critical factor and were directly deemed as not transferable.

Transferability of economic evaluations across jurisdictions: ISPOR Good Research Practices Task Force report

ABSTRACT A growing number of jurisdictions now request economic data in support of their decision-making procedures for the pricing and/or reimbursement of health technologies. Because more jurisdictions request economic data, the burden on study sponsors and researchers increases. There are many reasons why the cost-effectiveness of health technologies might vary from place to place. Therefore, this report of an ISPOR Good Practices Task Force reviews what national guidelines for economic evaluation say about transferability, discusses which elements of data could potentially vary from place to place, and recommends good research practices for dealing with aspects of transferability, including strategies based on the analysis of individual patient data and based on decision-analytic modeling.

Information on center characteristics as costs' determinants in multicenter clinical trials: is modeling center effect worth the effort?

OBJECTIVES

Several methodological problems arise when health outcomes and resource utilization are collected at different sites. To avoid misleading conclusions in multi-center economic evaluations the center effect needs to be taken into adequate consideration. The aim of this article is to compare several models, which make use of a different amount of information about the enrolling center.

METHODS

To model the association of total medical costs with the levels of two sets of covariates, one at patient and one at center level, we considered four statistical models, based on the Gamma model in the class of the Generalized Linear Models with a log link, which use different amount of information on the enrolling centers. Models were applied to Cost of Strategies after Myocardial Infarction data, an international randomized trial on costs of uncomplicated acute myocardial infarction (AMI).

RESULTS

The simple center effect adjustment based on a single random effect results in a more conservative estimation of the parameters as compared with approaches which make use of deeper information on the centers characteristics.

CONCLUSIONS

This study shows, with reference to a real multicenter trial, that center information cannot be neglected and should be collected and inserted in the analysis, better in combination with one or more random effect, taking into account in this way also the heterogeneity among centers because of unobserved centers characteristics.

Cost-effectiveness analysis of budesonide/formoterol maintenance and reliever therapy versus fixed combination treatments for asthma in Finland*

BACKGROUND

Budesonide/formoterol maintenance and reliever therapy has shown its effectiveness as a treatment for moderate-to-severe asthma.

OBJECTIVE

To explore the cost-effectiveness of budesonide/formoterol maintenance and reliever therapy as compared to fixed combination therapies (budesonide/formoterol and salmeterol/fluticasone) with terbutaline as needed in the treatment of asthma in Finland.

METHODS

Patients without asthma exacerbations during a 6-month period were used as the effectiveness variable in the within-trial economic analysis. Finnish unit costs were applied to pooled resource use data, and multinomial cost-effectiveness plane and acceptability curves were formed based on bootstrapping.

RESULTS

Use of budesonide/formoterol maintenance and reliever therapy significantly reduced the rate of severe asthma exacerbations as compared with a fixed dose of budesonide/formoterol or salmeterol/fluticasone and terbutaline as needed. Total costs over 6 months were 496 euros per patient for those who used the budesonide/formoterol maintenance and reliever therapy treatment model, which was 78-101 euros lower than the cost of fixed combinations of salmeterol/fluticasone or budesonide/formoterol with terbutaline as needed. The results indicate that the budesonide/formoterol maintenance and reliever therapy achieves a high probability (> 93%) of cost effectiveness irrespective of willingness to pay level.

CONCLUSIONS

Budesonide/formoterol maintenance and reliever therapy may be considered in the treatment of moderate-to-severe asthma instead of conventional treatment with combination products in view of its good clinical efficacy and a high probability of cost-effectiveness in the Finnish setting. However, a cost-effectiveness analysis with a longer time horizon, more Finnish-specific data, and ICS + short/long-acting inhaled beta(2)-agonist as an additional comparator is still warranted.

Cost-effectiveness analysis of a multinational RCT with a binary measure of effectiveness and an interacting covariate

In a recent multinational randomized clinical trial, 1356 patients from 14 countries were randomized between two arms. The primary measure of effectiveness was 30-day survival. Health care utilization was collected on all patients and was combined with a single country's price weights to provide patient-level cost data. The purpose of this paper is to report the results of the cost-effectiveness analysis for the country that provided the cost weights, so as to provide a case study for illustrating recently proposed methodologies that account for skewed cost data, the between-country variation in treatment effects, possible interactions between treatment and baseline covariates, and the difficulty of estimated adjusted risk differences. A hierarchal model is used to account for the two sources of variation (between country and between patients, within a country). The model, which uses gamma distributions for cost data and recent methods for estimating adjusted risk differences, provides overall and country-specific estimates of treatment effects. Model estimation is facilitated by Markov chain Monte Carlo methods using the WinBUGS software. In addition, the theory of expected value of information is used to determine if the data provided by the trial are sufficient for decision making.

The costs of treating acute heart failure: an economic analysis of the SURVIVE trial

OBJECTIVE

To estimate the incremental cost per life year gained with levosimendan relative to dobutamine in treatment of acute heart failure based on the Survival of Patients with Acute Heart Failure in Need of Intravenous Inotropic Support (SURVIVE) trial.

METHODS

SURVIVE enrolled 1,327 patients (levosimendan 664, dobutamine 663) from nine nations with 180-day survival from date of randomisation as the primary endpoint. Hospital resource utilisation was determined via clinical case reports. Unit costs were derived from hospital payment schedules for France, Germany and the UK, and represent a third-party payer perspective. Cost-effectiveness analysis was performed for a subset of the SURVIVE patient population selected in accordance with current levosimendan labeling.

RESULTS

Mortality in the levosimendan group was 26 versus 28% for dobutamine (hazard ratio 0.91, 95% confidence interval 0.74-1.13, p=0.40). Initial hospitalisation length of stay was identical (levosimendan 14.4, dobutamine 14.5, p=0.98). Slightly lower rates of readmission were observed for levosimendan relative to dobutamine at 31 (p=0.13) and 180 days (p=0.23). Mean costs excluding study drug were equivalent for the index admission (levosimendan euro5,060, dobutamine euro4,952; p=0.91) and complete episode (levosimendan euro5,396, dobutamine euro5,275; p=0.93).

CONCLUSION

At an acquisition cost of euro600 per vial, there is at least 50% likelihood that levosimendan is cost effective relative to dobutamine if willingness to pay is equal to or greater than euro15,000 per life year gained.

Multilevel models for estimating incremental net benefits in multinational studies

Multilevel models (MLMs) have been recommended for estimating incremental net benefits (INBs) in multicentre cost-effectiveness analysis (CEA). However, these models have assumed that the INBs are exchangeable and that there is a common variance across all centres. This paper examines the plausibility of these assumptions by comparing various MLMs for estimating the mean INB in a multinational CEA. The results showed that the MLMs that assumed the INBs were exchangeable and had a common variance led to incorrect inferences. The MLMs that included covariates to allow for systematic differences across the centres, and estimated different variances in each centre, made more plausible assumptions, fitted the data better and led to more appropriate inferences. We conclude that the validity of assumptions underlying MLMs used in CEA need to be critically evaluated before reliable conclusions can be drawn.

Cost-effectiveness analysis using data from multinational trials: the use of bivariate hierarchical modeling

Health care cost-effectiveness analysis (CEA) often uses individual patient data (IPD) from multinational randomized controlled trials. Although designed to account for between-patient sampling variability in the clinical and economic data, standard analytical approaches to CEA ignore the presence of between-location variability in the study results. This is a restrictive limitation given that countries often differ in factors that could affect the results of CEAs, such as the availability of health care resources, their unit costs, clinical practice, and patient case mix. The authors advocate the use of Bayesian bivariate hierarchical modeling to analyze multinational cost-effectiveness data. This analytical framework explicitly recognizes that patient-level costs and outcomes are nested within countries. Using real-life data, the authors illustrate how the proposed methods can be applied to obtain (a) more appropriate estimates of overall cost-effectiveness and associated measure of sampling uncertainty compared to standard CEA and (b) country-specific cost-effectiveness estimates that can be used to assess the between-location variability of the study results while controlling for differences in country-specific and patient-specific characteristics. It is demonstrated that results from standard CEA using IPD from multinational trials display a large degree of variability across the 17 countries included in the analysis, producing potentially misleading results. In contrast, "shrinkage estimates'' obtained from the modeling approach proposed here facilitate the appropriate quantification of country-specific cost-effectiveness estimates while weighting the results based on the level of information available within each country. The authors suggest that the methods presented here represent a general framework for the analysis of economic data collected from different locations.

Addressing the issues that arise in analysing multicentre cost data, with application to a multinational study

Differences in the mean, spread and skewness of cost data collected from different countries present problems for analysis and interpretation. Here we develop generalised linear multilevel models to estimate the effects of patient and national characteristics on costs. Using gamma distributions and multiplicative effects for patient characteristics fitted the data better than models which assumed normal distributions or estimated additive effects. A multilevel gamma model is employed to allow for heterogeneity in the effects of patient case-mix across centres. Analysis of multinational cost data must recognise differences in mean, spread and skewness across centres, as well as the data's hierarchical structure.

Analytic considerations in economic evaluations of multinational cardiovascular clinical trials

OBJECTIVES

The growing number of economic evaluations that use data collected in multinational clinical trials raises numerous questions regarding their execution and interpretation. Although recommendations for conducting economic evaluations have been widely disseminated, relatively little guidance has been given for conducting economic evaluations alongside clinical trials, particularly multinational trials.

METHODS

Building on a literature review that was conducted in preparation for an expert workshop, we evaluated a subset of methodological issues related to conducting economic evaluations alongside multinational clinical trials.

RESULTS

We found wide variation in the types of costs included as part of the analyses and in the methods used to assign costs to hospitalization events. Furthermore, we found that the extrapolation of costs and survival outcomes beyond the trial period is an inconsistent practice and is often not dependent on whether a survival benefit was observed in the trial or on the epidemiology or practice patterns in the country to which the findings are directed.

CONCLUSIONS

Although the limited sample size precluded a quantitative analysis of trial characteristics and their associations with the methodologies employed, our findings highlight the need for more guidance to analysts regarding the execution of economic evaluations using data from multinational clinical trials. As the research community grapples with the complexities of methodological and logistical issues involved in multinational economic evaluations, the development of a standardized format to report the basic methodological characteristics of such studies would help to improve transparency and comparability for other analysts and decision-makers.

Principles for the design of the economic evaluation of COLOR II: an international clinical trial in surgery comparing laparoscopic and open surgery in rectal cancer

OBJECTIVES

The objective is to describe the principles for the design of the economic evaluation of COLOR II, a randomized, multi-country study comparing laparoscopic and open surgery for rectal cancer.

METHODS

By using the experiences gained in a recent economic evaluation in colon cancer, where the same surgical techniques were compared, we could improve the method for identifying and measuring resource use items and also accommodate the use of data from the global study population.

RESULTS

In the design of the study, the uncertainty in the resource-use variables was reduced by considering (i) what aspects drive each variable, (ii) what resource use is related to the intervention, (iii) how data from different countries affects the variable.

CONCLUSIONS

The aim was to refine the data collection so that the economic research question could be answered in the best possible way, given the circumstances in the clinical study. Thus, (i) some variables were treated as stochastic variables and others as deterministic variables, (ii) aggregate key cost-driving resource items were developed that corresponded to clinical events, and (iii) a surrogate variable was selected, instead of the "obvious variable", to reduce the impact of confounding factors for one particular resource unit.

'Lost in translation': accounting for between-country differences in the analysis of multinational cost-effectiveness data

Cost-effectiveness analysis has gained status over the last 15 years as an important tool for assisting resource allocation decisions in a budget-limited environment such as healthcare. Randomised (multicentre) multinational controlled trials are often the main vehicle for collecting primary patient-level information on resource use, cost and clinical effectiveness associated with alternative treatment strategies. However, trial-wide cost effectiveness results may not be directly applicable to any one of the countries that participate in a multinational trial, requiring some form of additional modelling to customise the results to the country of interest. This article proposes an algorithm to assist with the choice of the appropriate analytical strategy when facing the task of adapting the study results from one country to another. The algorithm considers different scenarios characterised by: (a) whether the country of interest participated in the trial; and (b) whether individual patient-level data (IPD) from the trial are available. The analytical options available range from the use of regression-based techniques to the application of decision-analytic models. Decision models are typically used when the evidence base is available exclusively in summary format whereas regression-based methods are used mainly when the country of interest actively recruited patients into the trial and there is access to IPD (or at least country-specific summary data). Whichever method is used to reflect between-country variability in cost-effectiveness data, it is important to be transparent regarding the assumptions made in the analysis and (where possible) assess their impact on the study results.

Analysis sans frontières: can we ever make economic evaluations generalisable across jurisdictions?

Over the last decade or so, a number of healthcare systems have used economic evaluations as a formal input into decisions about the coverage or reimbursement of new healthcare interventions. This change in the policy landscape has placed some important demands on the design and characteristics of economic evaluation and these are increasingly evident in studies being presented to decision makers. One challenge has been to make studies specific to the context in which the decision is being taken. This is because of the inevitable geographical variation in many of the parameters within an analysis. There has been a series of important contributions to the published literature in recent years on how to quantify geographical heterogeneity within economic analyses based on randomised controlled trials. However, there are good reasons for economic evaluation for decision making to be undertaken using methods of evidence synthesis and decision analytical modelling, but issues of geographical variation still need to be handled appropriately. The key requirements of economic evaluations for decision making within healthcare systems can be defined as follows: (i) a design that meets the objectives and constraints of the healthcare system; (ii) coherent and complete specification of the decision problem; (iii) inclusion of all relevant evidence; and (iv) recognition and appropriate handling of uncertainty. In satisfying these requirements, it is important to be aware of variation between jurisdictions, and this imposes some important analytical requirements on economic studies. While many agencies have produced guidelines on preferred methods for healthcare economic evaluation, these exhibit considerable variation. Some of this variation can be justified by genuine differences between systems in clinical practice, objectives and constraints, while some of the variation relates to differences of opinion about appropriate analysis given methodological uncertainty. However, some of the variation in guidance is difficult to justify and is inconsistent with the aims and objectives of the systems the analyses are seeking to inform. Decision makers and analysts need to work together to streamline and where possible harmonise guidelines on methods for economic evaluations, whilst recognising legitimate variation in the needs of different healthcare systems. Otherwise, there is the risk that scarce resources will be wasted in producing country-specific analyses in situations where these are not justified. Expected value of information analyses are also emerging as a tool that could be considered by decision makers to guide their policy on the acceptance or non-acceptance of data from other jurisdictions.

Methods for incorporating covariate adjustment, subgroup analysis and between-centre differences into cost-effectiveness evaluations

BACKGROUND

Overall assessments of cost-effectiveness are now commonplace in informing medical policy decision making. It is often important, however, also to investigate how cost-effectiveness varies between patient subgroups. Yet such analyses are rarely undertaken, because appropriate methods have not been sufficiently developed.

METHODS

We propose a coherent set of Bayesian methods to extend cost-effectiveness analyses to adjust for baseline covariates, to investigate differences between subgroups, and to allow for differences between centres in a multicentre study using a hierarchical model. These methods consider costs and effects jointly, and allow for the typically skewed distribution of cost data. The results are presented as inferences on the cost-effectiveness plane, and as cost-effectiveness acceptability curves.

RESULTS

In applying these methods to a randomised trial of case management of psychotic patients, we show that overall cost-effectiveness can be affected by ignoring the skewness of cost data, but that it may be difficult to gain substantial precision by adjusting for baseline covariates. While analyses of overall cost-effectiveness can mask important subgroup differences, crude differences between centres may provide an unrealistic indication of the true differences between them.

CONCLUSIONS

The methods developed allow a flexible choice for the distributions used for cost data, and have a wide range of applicability--to both randomised trials and observational studies. Experience needs to be gained in applying these methods in practice, and using their results in decision making.

Good research practices for cost-effectiveness analysis alongside clinical trials: the ISPOR RCT-CEA Task Force report

OBJECTIVES

A growing number of prospective clinical trials include economic end points. Recognizing the variation in methodology and reporting of these studies, the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) chartered the Task Force on Good Research Practices: Randomized Clinical Trials-Cost-Effectiveness Analysis. Its goal was to develop a guidance document for designing, conducting, and reporting cost-effectiveness analyses conducted as a part of clinical trials.

METHODS

Task force cochairs were selected by the ISPOR Board of Directors. Cochairs invited panel members to participate. Panel members included representatives from academia, the pharmaceutical industry, and health insurance plans. An outline and a draft report developed by the panel were presented at the 2004 International and European ISPOR meetings, respectively. The manuscript was then submitted to a reference group for review and comment.

RESULTS

The report addresses issues related to trial design, selecting data elements, database design and management, analysis, and reporting of results. Task force members agreed that trials should be designed to evaluate effectiveness (rather than efficacy), should include clinical outcome measures, and should obtain health resource use and health state utilities directly from study subjects. Collection of economic data should be fully integrated into the study. Analyses should be guided by an analysis plan and hypotheses. An incremental analysis should be conducted with an intention-to-treat approach. Uncertainty should be characterized. Manuscripts should adhere to established standards for reporting results of cost-effectiveness analyses.

CONCLUSIONS

Trial-based cost-effectiveness studies have appeal because of their high internal validity and timeliness. Improving the quality and uniformity of these studies will increase their value to decision makers who consider evidence of economic value along with clinical efficacy when making resource allocation decisions.

Cost effectiveness of losartan in patients with hypertension and LVH: an economic evaluation for Sweden of the LIFE trial

OBJECTIVE

Evaluate the cost effectiveness of losartan compared with atenolol from a Swedish national health system perspective.

DESIGN

The Losartan Intervention For Endpoint reduction in hypertension study (LIFE) was a double-masked, randomized trial of losartan versus atenolol in 9193 patients with essential hypertension and left ventricular hypertrophy (LVH) ascertained by electrocardiography. Losartan reduced the primary composite end point of cardiovascular death, myocardial infarction (MI), or stroke by 13% (P = 0.021) and reduced the risk of stroke by 25% (P = 0.001), despite a comparable degree of blood pressure control.

METHODS

Life years gained was estimated by combining the absolute risk reduction in stroke with the life years gained by preventing stroke. Quality-adjusted life years (QALYs) gained was estimated by combining the absolute risk reduction in stroke with the QALYs gained by preventing stroke. QALYs were estimated by weighting life years by health-related quality of life (QoL), as measured with visual analogue scale (VAS) data collected in the trial. Net costs were defined as the total of study medication cost, stroke-related costs, and costs of increased survival. Costs are in 2003 Swedish prices. All costs and effects were discounted at a 3% annual rate.

RESULTS

Prevention of a stroke resulted in a gain of 5.7 life years and 4.3 QALYs. As a consequence, losartan treatment resulted in a per patient increase of 0.092 life years [95% confidence interval (CI): 0.038, 0.146] and 0.069 QALYs (95% CI: 0.028, 0.109) as compared with atenolol treatment. Losartan reduced direct stroke-related cost per patient by 1141 euros due to a lower cumulative incidence of stroke for losartan at 5.5 years (4.9%) as compared with atenolol (6.5%) (95% CI of difference: 0.7, 2.5). The reduction in stroke-related cost offset 80% of the added cost of losartan drug therapy. After inclusion of study medication cost, net cost per patient was 289 euros higher for losartan than atenolol. The net cost per QALY gained for losartan was 4188 euros (37,813 SEK), which is well within common Swedish benchmark upper values (200-500,000 SEK) for accepted cost-effective interventions.

CONCLUSION

Based on the results from the LIFE trial, treatment with losartan compared with atenolol, in hypertensive patients with LVH, is a cost-effective intervention.

Assessing generalisability by location in trial-based cost-effectiveness analysis: the use of multilevel models

Cost-effectiveness analysis (CEA) in health care is increasingly conducted alongside multicentre and multinational randomised controlled clinical trials (RCTs). The increased use of stochastic CEA is designed to account for between-patient sampling variability in cost-effectiveness data assuming that observations are independently distributed. However, between-location variability in cost-effectiveness may result if there is a hierarchical structure in the data; that is, if there is correlation in costs and outcomes between patients recruited in particular locations. This may be expected in multi-location trials given that centres and countries often differ in factors such as clinical practice, patient case-mix and the unit costs of delivering health care. A failure to acknowledge this feature may lead to misleading conclusions in a trial-based economic study. Multilevel modelling (MLM) is an analytical framework that can be used to handle hierarchical cost-effectiveness data. Using data from a recently conducted economic analysis, this paper shows how multilevel modelling can be used to obtain (a) more appropriate estimates of the population average incremental cost-effectiveness and associated standard errors compared to standard stochastic CEA; and (b) location-specific estimates of incremental cost-effectiveness which can be used to explore appropriately the variability between centres/countries of the cost-effectiveness results.

Increasing the generalizability of economic evaluations: Recommendations for the design, analysis, and reporting of studies

Objectives:Health technology assessment (HTA) is increasingly an international activity, and HTA agencies collaborate to avoid unnecessary duplication of effort. However, the sharing of the results from HTAs raises questions about their generalizability; namely, are the results of an HTA undertaken in one country relevant to another?

Methods:This study presents recommendations for increasing the generalizability of economic evaluations. They represent an important component of HTAs and are commonly thought to have limited generalizability.

Results:Recommendations are given for studies using patient-level data (i.e., evaluations conducted alongside clinical trials) and for studies using decision analytic modeling.

Conclusions:If implemented, the recommendations would increase the value for investments in HTA.

Health-care decision-making processes in Latin America: problems and prospects for the use of economic evaluation

OBJECTIVES

The use of economic evaluation studies (EE) in the decision-making process within the health-care system of nine Latin American (LA) and three European countries was investigated. The aim was to identify the opportunities, obstacles, and changes needed to facilitate the introduction of EE as a formal tool in health-care decision-making processes in LA.

METHODS

A comparative study was conducted based on existing literature and information provided through a questionnaire applied to decision makers in Argentina, Brazil, Colombia, Cuba, Mexico, Nicaragua, Peru, Portugal Spain, United Kingdom, Uruguay, and Venezuela. Systematic electronic searches of HEED, NHS EED, and LILACS were conducted to identify published economic evaluation studies in LA from 1982 onward.

RESULTS

There is relatively little evidence of the conduct and use of EE within the health care systems in LA. Electronic searches retrieved 554 records; however, only 93 were EE. In the nine LA participating countries, broad allocation of health-care resources is primarily based on political criteria, historical records, geographical areas, and specific groups of patients and diseases. Public-health provision and inclusion of services in health-insurance package are responsibilities of the Ministry of Health. Decisions regarding the purchase of medicines are primarily made through public tenders, and mainly based on differences in clinical efficacy and the price of health technologies of interest.

CONCLUSIONS

To expedite the process of incorporating EE as a formal tool to inform decision-making processes within the health-care systems in LA countries, two main conditions need to be fulfilled. First, adequate resources and skills need to be available to conduct EE of good quality. Second, decision-making procedures need to be modified to accommodate "evidence-based" approaches such as EE.

Meta-analysis and structured literature review in radiology

The overall goal of a systematic review or meta-analysis is to combine results of previous studies to arrive at summary conclusions about a body of research. In radiology, systematic reviews or meta-analyses can be used to calculate a summary estimate of effect size of a treatment that used imaging data to assess outcomes in observational or randomized controlled clinical trials, estimate the clinical effectiveness of an imaging-guided therapy procedure, evaluate the summary diagnostic accuracy of an imaging test, or synthesize results of economic evaluations that used imaging data. This article outlines the general concepts of structured literature reviews and discusses the approaches for conducting a meta-analysis in radiology, emphasizing the methods available for data synthesis and handling heterogeneity between and among studies.

Collecting unit cost data in multicentre studies. Creating comparable methods

International comparisons of health care systems and services have created increased interest in the comparability of cost results. This study compared top-down and bottom-up approaches to collecting unit cost data across centres in the context of examining the cost-effectiveness of dialysis therapy across Europe. The study tested whether health care technologies in different countries can be costed using consistent and transparent methods to increase the comparability of results. There was more agreement across the approaches for peritoneal dialysis than for than haemodialysis, with differences, respectively of Euro 91-1,687 vs. 333-7,314 per patient per year. Haemodialysis results showed greatest differences where dialysis units were integrated as part of larger hospitals. Deciding which approach to adopt depends largely on the technology. However, bottom-up costing should be considered for technologies with a large component of staff input or overheads, significant sharing of staff or facilities between technologies or patient groups and health care costing systems which do not routinely allocate costs to the intervention level. In these circumstances this costing approach could increase consistency and transparency and hence comparability of cost results.

Conducting economic evaluations alongside multinational clinical trials: toward a research consensus

Demand for economic evaluations in multinational clinical trials is increasing, but there is little consensus about how such studies should be conducted and reported. At a workshop in Durham, North Carolina, we sought to identify areas of agreement about how the primary findings of economic evaluations in multinational clinical trials should be generated and presented. In this paper, we propose a framework for classifying multinational economic evaluations according to (a) the sources of an analyst's estimates of resource use and clinical effectiveness and (b) the analyst's method of estimating costs. We review existing studies in the cardiology literature in the context of the proposed framework. We then describe important methodological and practical considerations in conducting multinational economic evaluations and summarize the advantages and disadvantages of each approach. Finally, we describe opportunities for future research. Delineation of the various approaches to multinational economic evaluation may assist researchers, peer reviewers, journal editors, and decision makers in evaluating the strengths and limitations of particular studies.

Using multilevel models for assessing the variability of multinational resource use and cost data

Multinational economic evaluations often calculate a single measure of cost-effectiveness using cost data pooled across several countries. To assess the validity of pooling international cost data the reasons for cost variation across countries need to be assessed. Previously, ordinary least-squares (OLS) regression models have been used to identify factors associated with variability in resource use and total costs. However, multilevel models (MLMs), which accommodate the hierarchical structure of the data, may be more appropriate. This paper compares these different techniques using a multinational dataset comprising case-mix, resource use and cost data on 1300 stroke admissions from 13 centres in 11 European countries. OLS and MLMs were used to estimate the effect of patient and centre-level covariates on the total length of hospital stay (LOS) and total cost. MLMs with normal and gamma distributions for the data within centres were compared. The results from the OLS model showed that both patient and centre-level covariates were associated with LOS and total cost. The estimates from the MLMs showed that none of the centre-level characteristics were associated with LOS, and the level of spending on health was the centre-level variable most highly associated with total cost. We conclude that using OLS models for assessing international variation can lead to incorrect inferences, and that MLMs are more appropriate for assessing why resource use and costs vary across centres.

Variability of cost-effectiveness estimates for pharmaceuticals in Western Europe: lessons for inferring generalizability

OBJECTIVES

It has long been suggested that, whereas the results of clinical studies of pharmaceuticals are generalizable from one jurisdiction to another, the results of economic evaluations are location dependent. There has been, however, little study of the causes of variation, whether differences in study results among countries are systematic, or whether they are important for decision making.

METHODS

A literature search was conducted to identify economic evaluations of pharmaceuticals conducted in two or more European countries. The studies identified were then classified by methodological type and analyzed to assess their level of variability and to identify the main causes of variation. Assessments were also made of the extent to which differences in study results among countries were systematic and whether they would lead to a different decision, assuming a range of values of the threshold willingness-to-pay for a life-year or quality-adjusted life-year (QALY).

RESULTS

In total 46 intercountry drug comparisons were identified, 29 in multicountry studies and 17 in comparable single country studies that were considered to be sufficiently similar in terms of methodology. The type of study (i.e., trial-based or modeling study) had some impact on variability, but the most important factor was the extent of variation across countries in effectiveness, resource use or unit costs, allowed by the researcher's chosen methodology. There were few systematic differences in study results among countries, so a decision maker in country B, on seeing a recent economic evaluation of a new drug in country A, would have little basis on which to predict whether the drug, if evaluated, would be more or less cost-effective in his or her country. Given the extent of variation in cost-effectiveness estimates among countries, the importance of this for decision making depends on decision makers' thresholds in willingness-to-pay for a QALY or life-year. If a cost-effectiveness threshold (i.e., willingness-to-pay) for a life-year or QALY of dollar 50,000 were assumed, the same conclusion regarding cost-effectiveness would be reached in most cases.

CONCLUSION

This review shows that cost-effectiveness results for pharmaceuticals vary from country to country in Western Europe and that these variations are not systematic. In addition, constraints imposed by analysts may reduce apparent variability in the estimates. The lessons for inferring generalizability are not straightforward, although the implications of variation for decision making depend critically on the cost-effectiveness thresholds applying in Western Europe.

Cost-effectiveness analysis for multinational clinical trials

Clinical trials of cost-effectiveness are often conducted in more than one country. The two most common ways of dealing with the multinational nature of the data are either to calculate a pooled estimate or to stratify results by country. Since the between-country heterogeneity in costs is potentially substantial, pooled estimates may be difficult to interpret for any one country. Policy decisions are often made at a national level, and so country-specific results are important. However, country-specific analyses will be based on fewer patients and will often fail to provide adequate precision for statistical analyses. Shrinkage estimation is a compromise between these two methods and has been used successfully in other fields. These estimates are country-specific yet less variable than those derived through a subgroup approach. Univariate and multivariate shrinkage estimators for costs and effects are proposed, then compared with one another and to the traditional methods in a simulation study. The methods are illustrated using data from a multinational trial evaluating the cost-effectiveness of three thrombolytic drug regimens in patients with acute myocardial infarction.