Sequences of biological treatments for patients with moderate-to-severe rheumatoid arthritis in the era of treat-to-target in China: a cost-effectiveness analysis

BACKGROUND

Biologic disease-modifying antirheumatic drugs (bDMARDs) are recommended to be added in sequentially in the treatment of moderate-to-severe rheumatoid arthritis (RA). All these drugs, however, are substantially more expensive than conventional synthetic DMARDs throughout the world, including in China. The objective of this study is to evaluate the cost-effectiveness of treatment sequences of bDMARDs for patients with moderate-to-severe rheumatoid arthritis from the Chinese healthcare system perspective.

METHODS

An individual patient simulation model was used to track the course of patients from first treatment through switches to further lines in a sequence. The comparator treatment sequence commenced with methotrexate, followed by non-biologic therapy. The intervention sequences were assumed to be the combinations of bDMARDs available, followed by non-biologic therapy. Life-years, quality-adjusted life-years (QALYs), and lifetime costs were estimated. Univariable and probabilistic sensitivity analyses and scenario analyses were performed to evaluate the model uncertainty.

RESULTS

Compared with the comparator treatment sequence, bDMARDs sequences were associated with more life years, QALYs, and cost. These produced ICERs ranged from $27,441.36/QALY to $40,149.2/QALY, above the willingness-to-pay threshold of $10,378 per QALY. The uncertainty analyses and the scenario analyses confirmed the result of the base case analysis.

CONCLUSIONS

From the perspective of the Chinese healthcare system, bDMARDs sequences are estimated not to be cost-effective compared with conventional synthetic disease-modifying antirheumatic drug strategy for patients with moderate-to-severe RA at a WTP threshold of $10,378 per QALY. Price reductions are warranted to make bDMARDs cost-effective and affordable.

Tofacitinib in the Treatment of Moderate-to-Severe Rheumatoid Arthritis in China: A Cost-Effectiveness Analysis Based on a Mapping Algorithm Derived from a Chinese Population

INTRODUCTION

To estimate the cost-effectiveness of tofacitinib for patients with moderate-to-severe rheumatoid arthritis (RA) who failed conventional synthetic disease-modifying antirheumatic drugs from the Chinese healthcare system perspective.

METHODS

An individual patient simulation model was used to estimate the lifetime cost and effectiveness. The comparator sequence commenced with etanercept, followed by rituximab-tocilizumab- non-biologic therapy. The intervention sequences were assumed to add tofacitinib to different positions in the comparator sequence. Quality-of-life estimates were generated by mapping Health Assessment Questionnaire scores to utility with the algorithm derived from a Chinese population. Scenario analyses, univariable and probabilistic sensitivity analyses were performed to evaluate the model uncertainty.

RESULTS

Compared with the comparator sequence, patients receiving tofacitinib as the first-, second-, third- and fourth-line treatment gained additional 0.49, 0.59, 0.44 and 0.53 QALYs, respectively, and the use of tofacitinib as the first- and second-line treatment was less costly, whereas the use of tofacitinib as the third- and fourth-line treatment cost an additional $234,998 and $381,116, respectively. This produced an incremental cost-effectiveness ratio of $333.73 and $9669.34/QALY, respectively.

CONCLUSION

Tofacitinib is estimated to be dominant in both the first- and second-line settings and to be highly cost-effective in both the third- and fourth-line settings.

Cost-effectiveness of Triple Therapy vs. Biologic Treatment Sequence as First-line Therapy for Rheumatoid Arthritis Patients after Methotrexate Failure

Introduction

A clinical trial (RACAT) reported the noninferiority of triple therapy compared to biologic agents (etanercept + methotrexate), and previous studies confirmed that biologic disease-modifying antirheumatic drugs (bDMARDs) are more expensive but less beneficial than triple therapy for patients with rheumatoid arthritis (RA) in whom methotrexate (MTX) fails. However, from the perspective of the Chinese healthcare system, the cost-effectiveness of triple therapy versus bDMARD treatment sequences as a first-line therapy for patients with RA is still unclear.

Methods

An individual patient simulation model was used to extrapolate the lifetime cost and health outcomes by tracing patients from initial treatment through switches to further treatment lines in a sequence. Therapeutic efficacy and physical function were evaluated using the American College of Rheumatology (ACR) response, 28-Joint Disease Activity Score (DAS28), and Health Assessment Questionnaire score. All input parameters in the model were derived from published studies, national databases, local hospitals, and experts’ opinions. Both direct costs and indirect costs were taken into consideration. Probabilistic and one-way sensitivity analyses were performed to test the uncertainty of the model, as were multiple scenario analyses.

Results

The lifetime analysis demonstrated that triple therapy was associated with lower costs and quality-adjusted life years (QALYs) than bDMARD sequences. These resulted in incremental cost-effectiveness ratios (ICERs) ranging from $87,090/QALY to $104,032/QALY, higher than the willingness-to-pay (WTP) threshold in China ($30,950/QALY). The baseline DAS28 impacted the model outcomes the most. Scenario analyses indicated that adding triple therapy to bDMARD sequences as a first-, second-, third-, or fourth-line therapy is very cost-effective, at a WTP of $10,316/QALY.

Conclusions

From a Chinese payer perspective, triple therapy as first-line treatment in treatment sequence could be regarded as cost-effectiveness option for patients who failed MTX, compared to bDMARDs as first-line treatment, and instead of prescribing triple therapy as a substitute for bDMARDs as a first-line treatment, adding triple therapy to the bDMARD treatment sequence is likely to be very cost-effective for patients with active RA compared to bDMARD sequences.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00300-4.

The Effect of Dose Escalation on the Cost-Effectiveness of Etanercept and Adalimumab with Methotrexate Among Patients with Moderate to Severe Rheumatoid Arthritis

BACKGROUND

Patients with moderate to severe rheumatoid arthritis (RA) occasionally increase their doses of tumor necrosis factor (TNF) inhibitors, especially the monoclonal antibody origin drugs such as adalimumab and infliximab, after inadequate response to the initial dose. Previous studies have evaluated the cost-effectiveness of various sequences of treatment for RA in the United States but have not considered the effect of dose escalation.

OBJECTIVE

To assess the cost-effectiveness of etanercept and adalimumab by incorporating the effect of dose escalation in moderate to severe RA patients.

METHODS

We adapted the open-source Innovation and Value Initiative - Rheumatoid Arthritis model, version 1.0 to separately simulate the magnitude and time to dose escalation among RA patients taking adalimumab plus methotrexate or etanercept plus methotrexate from a societal perspective and lifetime horizon. An important assumption in the model was that dose escalation would increase treatment costs through its effect on the number of doses but would have no effect on effectiveness. We estimated the dose escalation parameters using the IBM MarketScan Commercial and Medicare Supplemental Databases. We fit competing parametric survival models to model time to dose escalation and used model diagnostics to compare the fit of the competing models. We measured the magnitude of dose escalation as the percentage increase in the number of doses conditional on dose escalation. Finally, we used the parameterized model to simulate treatment sequences beginning with a TNF inhibitor (adalimumab, etanercept) followed by nonbiologic treatment.

RESULTS

In baseline models without dose escalation, the incremental cost per quality-adjusted life-year of the etanercept treatment sequence relative to the adalimumab treatment sequence was $85,593. Incorporating dose escalation increased treatment costs for each sequence, but costs increased more with adalimumab, lowering the incremental cost-effectiveness ratio to $9,001. At willingness-to-pay levels of $100,000, the etanercept sequence was more cost-effective compared with the adalimumab sequence, with probability 0.55 and 0.85 in models with and without dose escalation, respectively.

CONCLUSIONS

Dose escalation has important effects on cost-effectiveness and should be considered when comparing biologic medications for the treatment of RA.

DISCLOSURES

Funding for this study was contributed by Amgen. When this work was conducted, Incerti and Jansen were employees of Precision Health Economics, which received financial support from Amgen. Maksabedian Hernandez, Collier, Gharaibeh, and Stolshek were employees and stockholders of Amgen, and Tkacz and Moore-Schiltz were employees of IBM Watson Health, which received financial support from Amgen. Some of the results of this work were previously presented as a poster at the 2019 AMCP Managed Care & Specialty Pharmacy Annual Meeting, March 25-28, 2019, in San Diego, CA.

Cost-effectiveness analysis of treatment sequences containing tofacitinib for the treatment of rheumatoid arthritis in Spain

Objective

To assess the cost-effectiveness of tofacitinib-containing treatment sequences versus sequences containing only standard biological therapies in patients with moderate-to-severe rheumatoid arthritis (RA) after the failure of conventional synthetic disease-modifying antirheumatic drugs (csDMARD-IR population) and in patients previously treated with methotrexate (MTX) who show an inadequate response to second-line therapy with any tumour necrosis factor inhibitor (TNFi-IR population).

Methods

A patient-level microsimulation model estimated, from the perspective of the Spanish Public NHS, lifetime costs and quality-adjusted life years (QALY) for treatment sequences starting with tofacitinib (5 mg twice daily) followed by biological therapies versus sequences of biological treatments only. Concomitant treatment with MTX was considered. Model’s parameters comprised demographic and clinical inputs (initial Health Assessment Questionnaire [HAQ] score and clinical response to short- and long-term treatment). Efficacy was measured by means of HAQ score changes using mixed treatment comparisons and data from long-term extension (LTE) trials. Serious adverse events (SAEs) data were derived from the literature. Total cost estimation (€, 2018) included drug acquisition, parenteral administration, disease progression and SAE management.

Results

In the csDMARD-IR population, sequences starting with tofacitinib proved dominant options (more QALYs and lower costs) versus the corresponding sequences without tofacitinib. In the TNFi-IR population, first-line treatment with tofacitinib+MTX followed by scAbatacept+MTX➔rituximab+MTX➔certolizumab+MTX proved dominant versus scTocilizumab+MTX➔scAbatacept+MTX➔rituximab+MTX➔certolizumab+MTX; and tofacitinib+MTX➔scTocilizumab+MTX➔scAbatacept+MTX➔rituximab+MTX versus scTocilizumab+MTX➔scAbatacept+MTX➔rituximab+MTX➔certolizumab+MTX was less effective but remained a cost-saving option.

Conclusions

Inclusion of tofacitinib seems a dominant strategy in moderate-to-severe RA patients after csDMARDs failure. Tofacitinib, as initial third-line therapy, proved a cost-saving strategy (€− 337,489/QALY foregone) in moderate-to-severe TNFi-IR RA patients.

Key points • Therapeutical approach in rheumatoid arthritis (RA) consisted in sequences of several therapies during patient lifetime. • Treatment sequences initiating with tofacitinib followed by biological drugs provided higher health effects in csDMARDs-IR population, compared with sequences containing only biological drugs. • In both csDMARD-IR and TNFi-IR RA populations, initiating treatment with tofacitinib was associated to lower treatment costs for the Spanish National Health System.

A Flexible Open-Source Decision Model for Value Assessment of Biologic Treatment for Rheumatoid Arthritis

OBJECTIVE

The nature of model-based cost-effectiveness analysis can lead to disputes in the scientific community. We propose an iterative and collaborative approach to model development by presenting a flexible open-source simulation model for rheumatoid arthritis (RA), accessible to both technical and non-technical end-users.

METHODS

The RA model is a discrete-time individual patient simulation with 6-month cycles. Model input parameters were estimated based on currently available evidence and treatment effects were obtained with Bayesian network meta-analysis techniques. The model contains 384 possible model structures informed by previously published models. The model consists of the following components: (i) modifiable R and C++ source code available in a GitHub repository; (ii) an R package to run the model for custom analyses; (iii) detailed model documentation; (iv) a web-based user interface for full control over the model without the need to be well-versed in the programming languages; and (v) a general audience web-application allowing those who are not experts in modeling or health economics to interact with the model and contribute to value assessment discussions.

RESULTS

A primary function of the initial version of RA model is to help understand and quantify the impact of parameter uncertainty (with probabilistic sensitivity analysis), structural uncertainty (with multiple competing model structures), the decision framework (cost-effectiveness analysis or multi-criteria decision analysis), and perspective (healthcare or limited societal) on estimates of value.

CONCLUSION

In order for a decision model to remain relevant over time it needs to evolve along with its supporting body of clinical evidence and scientific insight. Multiple clinical and methodological experts can modify or contribute to the RA model at any time due to its open-source nature.

Economic Evaluation of Sarilumab in the Treatment of Adult Patients with Moderately-to-Severely Active Rheumatoid Arthritis Who Have an Inadequate Response to Conventional Synthetic Disease-Modifying Antirheumatic Drugs

Introduction

Assess the cost-effectiveness (US healthcare payer perspective) of sarilumab subcutaneous (SC) 200 mg + methotrexate versus conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) or targeted DMARD + methotrexate for moderate-to-severe rheumatoid arthritis (RA) in adults with inadequate response to methotrexate.

Methods

Microsimulation based on patient profiles from MOBILITY (NCT01061736) was conducted via a 6-month decision tree and lifetime Markov model with 6-monthly cycles. Treatment response at 6 months was informed by a network meta-analysis and based on American College of Rheumatology (ACR) response. Responders: patients with ACR20 response who continued with therapy; non-responders: ACR20 non-responders who transitioned to the subsequent treatment. Utilities and quality-adjusted life-years (QALYs) were estimated via mapping 6-month ACR20/50/70 response to relative change in Health Assessment Questionnaire Disability Index score (short term) and based on published algorithms (long term). Direct costs considered drugs (wholesale acquisition costs), administration and routine care.

Results

Lifetime QALYs and costs for treatment sequences on the efficiency frontier were 3.43 and $115,019 for active csDMARD, 5.79 and $430,918 for sarilumab, and 5.94 and $524,832 for etanercept (all others dominated). Sarilumab was cost-effective versus tocilizumab and csDMARD (incremental cost-effectiveness ratios of $84,079/QALY and $134,286/QALY). Probabilistic sensitivity analysis suggested comparable costs and slightly improved health benefits for sarilumab versus tocilizumab, irrespective of threshold.

Conclusion

In patients with moderate-to-severe RA, sarilumab 200 mg SC every 2 weeks + methotrexate can be considered a cost-effective treatment option, with lower costs and greater health benefits than alternative treatment sequences (+ methotrexate) beginning with adalimumab, certolizumab, golimumab and tofacitinib and below commonly accepted cost-effectiveness thresholds against tocilizumab + methotrexate or csDMARD active treatment.

Funding

Sanofi and Regeneron Pharmaceuticals, Inc.

Electronic supplementary material

The online version of this article (10.1007/s12325-019-00946-1) contains supplementary material, which is available to authorized users.

Does intensive management improve remission rates in patients with intermediate rheumatoid arthritis? (the TITRATE trial): study protocol for a randomised controlled trial

Background

Uncontrolled active rheumatoid arthritis can lead to increasing disability and reduced quality of life over time. ‘Treating to target’ has been shown to be effective in active established disease and also in early disease. However, there is a lack of nationally agreed treatment protocols for patients with established rheumatoid arthritis who have intermediate disease activity. This trial is designed to investigate whether intensive management of disease leads to a greater number of remissions at 12 months. Levels of disability and quality of life, and acceptability and cost-effectiveness of the intervention will also be examined.

Methods

The trial is a 12-month, pragmatic, randomised, open-label, two-arm, parallel-group, multicentre trial undertaken at specialist rheumatology centres across England. Three hundred and ninety-eight patients with established rheumatoid arthritis will be recruited. They will currently have intermediate disease activity (disease activity score for 28 joints assessed using an erythrocyte sedimentation rate of 3.2 to 5.1 with at least three active joints) and will be taking at least one disease-modifying anti-rheumatic drug.

Participants will be randomly selected to receive intensive management or standard care. Intensive management will involve monthly clinical reviews with a specialist health practitioner, where drug treatment will be optimised and an individualised treatment support programme delivered based on several principles of motivational interviewing to address identified problem areas, such as pain, fatigue and adherence. Standard care will follow standard local pathways and will be in line with current English guidelines from the National Institute for Health and Clinical Excellence. Patients will be assessed initially and at 6 and 12 months through self-completed questionnaires and clinical evaluation.

Discussion

The trial will establish whether the known benefits of intensive treatment strategies in active rheumatoid arthritis are also seen in patients with established rheumatoid arthritis who have moderately active disease. It will evaluate both the clinical and cost-effectiveness of intensive treatment.

Trial registration

Current Controlled Trials, ID: ISRCTN70160382. Registered on 16 January 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2330-8) contains supplementary material, which is available to authorized users.

Cost-effectiveness of sequenced treatment of rheumatoid arthritis with targeted immune modulators

AIMS

To determine the cost-effectiveness of treatment sequences of biologic disease-modifying anti-rheumatic drugs or Janus kinase/STAT pathway inhibitors (collectively referred to as bDMARDs) vs conventional DMARDs (cDMARDs) from the US societal perspective for treatment of patients with moderately to severely active rheumatoid arthritis (RA) with inadequate responses to cDMARDs.

MATERIALS AND METHODS

An individual patient simulation model was developed that assesses the impact of treatments on disease based on clinical trial data and real-world evidence. Treatment strategies included sequences starting with etanercept, adalimumab, certolizumab, or abatacept. Each of these treatment strategies was compared with cDMARDs. Incremental cost, incremental quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for each treatment sequence relative to cDMARDs. The cost-effectiveness of each strategy was determined using a US willingness-to-pay (WTP) threshold of $150,000/QALY.

RESULTS

For the base-case scenario, bDMARD treatment sequences were associated with greater treatment benefit (i.e. more QALYs), lower lost productivity costs, and greater treatment-related costs than cDMARDs. The expected ICERs for bDMARD sequences ranged from ∼$126,000 to $140,000 per QALY gained, which is below the US-specific WTP. Alternative scenarios examining the effects of homogeneous patients, dose increases, increased costs of hospitalization for severely physically impaired patients, and a lower baseline Health Assessment Questionnaire (HAQ) Disability Index score resulted in similar ICERs.

CONCLUSIONS

bDMARD treatment sequences are cost-effective from a US societal perspective.

Toward health technology assessment of whole-genome sequencing diagnostic tests: challenges and solutions

Whole-genome sequencing (WGS) is being applied within research settings across Europe to develop genomic WGS-based diagnostic tests. The focus of this perspective paper is to describe if, and how, current approaches of health technology assessment could be applied to WGS-based diagnostic tests. This perspective draws on the collective view from a trans-European multidisciplinary consortium of methodologists, clinicians and scientists. Specific challenges can be described by using the PICO (population, intervention, comparator, outcome) framework to inform health technology assessment. Practical solutions are suggested which require joined-up, multidisciplinary working across healthcare systems using existing expert networks so that emergent issues for the health technology assessment of WGS can be met in a timely fashion.

Consensus Decision Models for Biologics in Rheumatoid and Psoriatic Arthritis: Recommendations of a Multidisciplinary Working Party

Introduction

Biologic therapies are efficacious but costly. A number of health economic models have been developed to determine the most cost-effective way of using them in the treatment pathway. These models have produced conflicting results, driven by differences in assumptions, model structure, and data, which undermine the credibility of funding decisions based on modeling studies. A Consensus Working Party met to discuss recommendations and approaches for future models of biologic therapies.

Methods

Our working party consisted of clinical specialists, modelers, and policy makers. Two 1-day meetings were held for members to arrive at consensus positions on model structure, assumptions, and appropriate data sources. These views were guided by clinical aspects of rheumatoid and psoriatic arthritis and the principles of evidence-based medicine. Where opinions differed, we sought to identify a research agenda that would generate the evidence needed to reach consensus.

Results

We gained consensus in four areas of model development: initial response to treatment; long-term disease progression; lifetime costs and benefits; and model structure. Consensus was also achieved on some key parameters such as choices of outcome measures, methods for extrapolation beyond trial data, and treatment switching. A research agenda to support further consensus was also identified.

Conclusion

Consensus guidance that fully reflects current evidence and clinical understanding was gained successfully. In addition, research needs have been identified. Such guidance can be updated as evidence develops and policy questions change and need not be prescriptive as long as deviations from consensus are clearly explained and justified.

Funding

Arthritis Research UK and the UK Medical Research Council Network of Hubs for Trials Methodology Research.

Electronic supplementary material

The online version of this article (doi:10.1007/s40744-015-0020-0) contains supplementary material, which is available to authorized users.

Cost-effectiveness of TNF inhibitors vs synthetic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis: a Markov model study based on two longitudinal observational studies

Objective. The objective of this study was to estimate the additional costs and health benefits of adding a TNF inhibitor (TNFi) (adalimumab, certolizumab, etanercept, golimumab, infliximab) to a synthetic DMARD (sDMARD), e.g. MTX, in patients with RA.

Methods. We developed the Norwegian RA model as a Markov model simulating 10 years of treatment with either TNFi plus sDMARDs (TNFi strategy) or sDMARDs alone (synthetic strategy). Patients in both strategies started in one of seven health states, based on the Short Form-6 Dimensions (SF-6D). The patients could move to better or worse health states according to transition probabilities. In the TNFi strategy, patients could stay on TNFi (including switch of TNFi), or switch to non-TNFi-biologics (abatacept, rituximab, tocilizumab), sDMARDs or no DMARD. In the synthetic strategy, patients remained on sDMARDs. Data from two observational studies were used for the assessment of resource use and utilities in the health states. Health benefits were evaluated using the EuroQol-5 Dimensions (EQ-5D) and SF-6D.

Results. The Norwegian RA model predicted that 10-year discounted health care costs totalled €124 942 (€475 266 including production losses) for the TNFi strategy and €65 584 (€436 517) for the synthetic strategy. The cost per additionally gained quality-adjusted life-year of adding a TNFi was €92 557 (€60 227 including production losses) using SF-6D and €61 285 (€39 841) using EQ-5D. Including health care costs only, the probability that TNFi treatment was cost-effective was 90% when using EQ-5D, assuming a Norwegian willingness-to-pay level of €67 300.

Conclusion. TNFi treatment for RA is cost-effective when accounting for production losses. Excluding production losses, TNFi treatment is cost-effective using EQ-5D, but not SF-6D.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Including adverse drug events in economic evaluations of anti-tumour necrosis factor-α drugs for adult rheumatoid arthritis: a systematic review of economic decision analytic models

BACKGROUND

Anti-tumour necrosis factor-α drugs (anti-TNFs) have revolutionised the treatment of rheumatoid arthritis (RA). More effective than standard non-biological disease-modifying anti-rheumatic drugs (nbDMARDs), anti-TNFs are also substantially more expensive. Consequently, a number of model-based economic evaluations have been conducted to establish the relative cost-effectiveness of anti-TNFs. However, anti-TNFs are associated with an increased risk of adverse drug events (ADEs) such as serious infections relative to nbDMARDs. Such ADEs will likely impact on both the costs and consequences of anti-TNFs, for example, through hospitalisations and forced withdrawal from treatment.

OBJECTIVE

The aim of this review was to identify and critically appraise if, and how, ADEs have been incorporated into model-based cost-effectiveness analyses of anti-TNFs for adult patients with RA.

METHODS

A systematic literature review was performed. Electronic databases (Ovid MEDLINE; Ovid EMBASE; Web of Science; NHS Economic Evaluations Database) were searched for literature published between January 1990 and October 2013 using electronic search strategies. The reference lists of retrieved studies were also hand searched. In addition, the National Institute for Health and Care Excellence technology appraisals were searched to identify economic models used to inform UK healthcare decision making. Only full economic evaluations that had used an economic model to evaluate biological DMARDs (bDMARDs) (including anti-TNFs) for adult patients with RA and had incorporated the direct costs and/or consequences of ADEs were critically appraised. To be included, studies also had to be available as a full text in English. Data extracted included general study characteristics and information concerning the methods used to incorporate ADEs and any associated assumptions made. The extracted data were synthesised using a tabular and narrative format.

RESULTS

A total of 43 model-based economic evaluations of bDMARDs for adult RA were identified from 2,483 initially identified studies (2,473 published; ten technology appraisals). Of these, nine studies had incorporated the incidence and costs of ADEs and were critically reviewed. One study also explicitly estimated the potential consequences for patient utility. There was a general lack of detail specifically reporting on how ADEs were included in the economic models. Furthermore, there was substantial heterogeneity amongst the nine studies concerning the (i) application of risk-related terminology; (ii) method of incorporating the incidence, costs and consequences of ADEs; and (iii) ADE-related assumptions.

CONCLUSIONS

Model-based economic evaluations have played an integral role in healthcare reimbursement and funding decisions relating to anti-TNFs for adult patients with RA. However, current economic models have not routinely or systematically considered the direct costs or consequences of ADEs, which may bias the estimates of the relative cost-effectiveness of anti-TNFs. Omitting information on relevant costs and consequences of interventions for RA will affect the validity of the associated recommendations for informed decision making. To improve current practice it is recommended that (i) greater efforts be made to provide appropriate long-term safety data on the use of anti-TNFs in adult RA; (ii) empirical research be undertaken to identify and quantify the impact of, and possible methods for, including ADEs in economic models to inform future good practice guidelines; and (iii) economic modelling guidelines and reference cases be updated to explicitly identify ADEs as an important treatment outcome and address how they might be incorporated into economic models. Improved consideration of the possible implications of ADEs in economic models will ensure that healthcare decision makers are provided with reliable and accurate information with which to make efficient reimbursement and financing decisions.

A comparison of direct and indirect methods for the estimation of health utilities from clinical outcomes

BACKGROUND

Analysts frequently estimate health state utility values from other outcomes. Utility values like EQ-5D have characteristics that make standard statistical methods inappropriate. We have developed a bespoke, mixture model approach to directly estimate EQ-5D. An indirect method, "response mapping," first estimates the level on each of the 5 dimensions of the EQ-5D and then calculates the expected tariff score. These methods have never previously been compared.

METHODS

We use a large observational database from patients with rheumatoid arthritis (N = 100,398). Direct estimation of UK EQ-5D scores as a function of the Health Assessment Questionnaire (HAQ), pain, and age was performed with a limited dependent variable mixture model. Indirect modeling was undertaken with a set of generalized ordered probit models with expected tariff scores calculated mathematically. Linear regression was reported for comparison purposes. Impact on cost-effectiveness was demonstrated with an existing model.

RESULTS

The linear model fits poorly, particularly at the extremes of the distribution. The bespoke mixture model and the indirect approaches improve fit over the entire range of EQ-5D. Mean average error is 10% and 5% lower compared with the linear model, respectively. Root mean squared error is 3% and 2% lower. The mixture model demonstrates superior performance to the indirect method across almost the entire range of pain and HAQ. These lead to differences in cost-effectiveness of up to 20%.

CONCLUSIONS

There are limited data from patients in the most severe HAQ health states. Modeling of EQ-5D from clinical measures is best performed directly using the bespoke mixture model. This substantially outperforms the indirect method in this example. Linear models are inappropriate, suffer from systematic bias, and generate values outside the feasible range.

An overview of models used in economic analyses of biologic therapies for arthritis--from current diversity to future consensus

A number of cost-effectiveness models have been developed with the aim of providing guidance for decision making on biologic therapies for the management of inflammatory joint disease. The findings of these analyses can differ markedly, and these differences can undermine the credibility of such models if unexplained. To allow differences between models to be identified more easily, we define six components common to all models-initial response, longer term disease progression, mortality, quality-adjusted life year estimation, resource use and the selection and interpretation of data. We give examples of divergent approaches taken by model structures to the same issue, and explore the impact of divergence on model results, with particular focus on two models that have reported substantially different estimates for the cost-effectiveness of third-line etanercept vs conventional DMARD. The sensitivity of results to a particular assumption made in a model will depend on the decision problem and assumptions made elsewhere in the model, highlighting the importance of guidance throughout model development. To some extent, guidance from bodies such as the National Institute of Health and Clinical Excellence can be used to determine which approach should be preferred where models differ. However, there is a pressing need for clinical input and guidance before consensus can be reached on the most credible model(s) to use for decision support.