Health technology assessment of treatment for peripheral arterial disease

Peripheral arterial disease (PAD) is a widespread cardiovascular disease that causes pain and reduces the patient’s ability to walk. The first objective of the thesis was to investigate current treatment patterns for PAD by identifying groups of PAD patients with different treatment needs according to their cardiovascular risk and their probability of undergoing invasive PAD treatment. As a result, three groups were identified. The second objective was to measure the quality of life of patients with PAD who receive different kinds of treatment, which showed a positive effect of all treatments, and to measure the costs of these treatments. Data from 245 Dutch PAD patients were used for these analyses. The final objective was to assess the cost-effectiveness of a new treatment strategy for PAD, rivaroxaban plus aspirin, by comparing the costs and health effects of the new treatment to those of existing treatments, treatment with aspirin or clopidogrel. The results of this analysis showed treatment with rivaroxaban plus aspirin was cost-effective overall but highlighted differences between patient groups

Exploring the Cost Effectiveness of Shared Decision Making for Choosing between Disease-Modifying Drugs for Relapsing-Remitting Multiple Sclerosis in the Netherlands:A State Transition Model

Background Up to 31% of patients with relapsing-remitting multiple sclerosis (RRMS) discontinue treatment with disease-modifying drug (DMD) within the first year, and of the patients who do continue, about 40% are nonadherent. Shared decision making may decrease nonadherence and discontinuation rates, but evidence in the context of RRMS is limited. Shared decision making may, however, come at additional costs. This study aimed to explore the potential cost-effectiveness of shared decision making for RRMS in comparison with usual care, from a (limited) societal perspective over a lifetime. Methods An exploratory economic evaluation was conducted by adapting a previously developed state transition model that evaluates the cost-effectiveness of a range of DMDs for RRMS in comparison with the best supportive care. Three potential effects of shared decision making were explored: 1) a change in the initial DMD chosen, 2) a decrease in the patient's discontinuation in using the DMD, and 3) an increase in adherence to the DMD. One-way and probabilistic sensitivity analyses of a scenario that combined the 3 effects were conducted. Results Each effect separately and the 3 effects combined resulted in higher quality-adjusted life years (QALYs) and costs due to the increased utilization of DMD. A decrease in discontinuation of DMDs influenced the incremental cost-effectiveness ratio (ICER) most. The combined scenario resulted in an ICER of euro17,875 per QALY gained. The ICER was sensitive to changes in several parameters. Conclusion This study suggests that shared decision making for DMDs could potentially be cost-effective, especially if shared decision making would help to decrease treatment discontinuation. Our results, however, may depend on the assumed effects on treatment choice, persistence, and adherence, which are actually largely unknown

Rivaroxaban plus aspirin for the prevention of ischaemic events in patients with cardiovascular disease:a cost-effectiveness study

Background Dual pathway inhibition with 2.5 mg rivaroxaban twice daily plus 100 mg aspirin once daily may be a promising alternative to 100 mg aspirin antiplatelet therapy for the prevention of cardiovascular events in patients with coronary artery disease and/or peripheral arterial disease. However, treatment costs and bleeding risks are higher, and there is another treatment option for peripheral arterial disease, 75 mg clopidogrel. A comprehensive assessment of benefits, risks and costs of dual pathway inhibition versus standard of care is needed. Methods We used a state transition model including cardiovascular, ischaemic limb and bleeding events to compare dual pathway inhibition to aspirin antiplatelet therapy in coronary artery disease, and additionally to clopidogrel antiplatelet therapy in peripheral arterial disease patients. We calculated the incremental cost-effectiveness ratio from costs and quality-adjusted life-years of lifelong treatment, and the cost-effectiveness probability at a euro50,000/quality-adjusted life-year threshold. Results Quality-adjusted life-years and costs of dual pathway inhibition were highest, the incremental cost-effectiveness ratios versus aspirin were euro32,109 in coronary artery disease and euro26,381 in peripheral arterial disease patients, with 92% and 56% cost-effectiveness probability, respectively (clopidogrel was extendedly dominated). Incremental cost-effectiveness ratios were below euro20,000 in comorbid peripheral arterial disease patients and coronary artery disease patients younger than 65 years, incremental cost-effectiveness ratios were above euro50,000 in carotid artery disease patients and coronary artery disease patients older than 75 years. Conclusion Lifelong preventive treatment of coronary artery disease and peripheral arterial disease patients at risk of cardiovascular events with dual pathway inhibition improves health outcomes and seems overall cost-effective relative to aspirin antiplatelet therapy and also to clopidogrel antiplatelet therapy for peripheral arterial disease, particularly in comorbid patients, but not in older patients and in carotid artery disease patients. These findings may warrant a targeted approach

Exploring the Feasibility of Comprehensive Uncertainty Assessment in Health Economic Modeling:A Case Study

Objectives: Decision makers adopt health technologies based on health economic models that are subject to uncertainty. In an ideal world, these models parameterize all uncertainties and reflect them in the cost-effectiveness probability and risk associated with the adoption. In practice, uncertainty assessment is often incomplete, potentially leading to suboptimal reimbursement recommendations and risk management. This study examines the feasibility of comprehensive uncertainty assessment in health economic models. Methods: A state transition model on peripheral arterial disease treatment was used as a case study. Uncertainties were identified and added to the probabilistic sensitivity analysis if possible. Parameter distributions were obtained by expert elicitation, and structural uncertainties were either parameterized or explored in scenario analyses, which were model averaged. Results: A truly comprehensive uncertainty assessment, parameterizing all uncertainty, could not be achieved. Expert elicitation informed 8 effectiveness, utility, and cost parameters. Uncertainties were parameterized or explored in scenario analyses and with model averaging. Barriers included time and resource constraints, also of clinical experts, and lacking guidance regarding some aspects of expert elicitation, evidence aggregation, and handling of structural uncertainty. The team's multidisciplinary expertise and existing literature and tools were facilitators. Conclusions: While comprehensive uncertainty assessment may not be attainable, improvements in uncertainty assessment in general are no doubt desirable. This requires the development of detailed guidance and hands-on tutorials for methods of uncertainty assessment, in particular aspects of expert elicitation, evidence aggregation, and handling of structural uncertainty. The issue of benefits of uncertainty assessment versus time and resources needed remains unclear

Comparison of three generic quality-of-life metrics in peripheral arterial disease patients undergoing conservative and invasive treatments

Purpose To determine the effect of revascularisation for peripheral arterial disease (PAD) on QoL in the first and second year following diagnosis, to compare the effect depicted by Short Form Six Dimensions (SF-6D) and EuroQoL five Dimensions (EQ-5D) utilities, and Visual Analogue Scale (VAS) scores and to analyse heterogeneity in treatment response. Methods Longitudinal data from 229 PAD patients were obtained in an observational study in southern Netherlands. Utility scores were calculated with the international (SF-6D) and Dutch (EQ-5D) tariffs. We analysed treatment effect at years 1 and 2 through propensity score-matched ANCOVAs. Thereby, we estimated the marginal means (EMMs) of revascularisation and conservative treatment, and identified covariates of revascularisation effect. Results A year after diagnosis, 70 patients had been revascularised; the EMMs of revascularisation were 0.038, 0.077 and 0.019 for SF-6D, EQ-5D and VAS, respectively (always in this order). For conservative treatment these were -0.017, 0.038 and 0.021. At 2-year follow-up, the EMMs of revascularisation were 0.015, 0.077 and 0.027, for conservative treatment these were -0.020, 0.013 and -0.004. Baseline QoL (and rest pain in year 2) were covariates of treatment effect. Conclusions We measured positive effects of revascularisation and conservative treatment on QoL a year after diagnosis, the effect of revascularisation was sustained over 2 years. The magnitude of effect varied between the metrics and was largest for the EQ-5D, which may be most suitable for QoL measurement in PAD patients. Baseline QoL influenced revascularisation effect, in clinical practice this may inform expected QoL gain in individual patients

Exploring the Cost Effectiveness of Shared Decision Making for Choosing between Disease-Modifying Drugs for Relapsing-Remitting Multiple Sclerosis in the Netherlands: A State Transition Model

Background Up to 31% of patients with relapsing-remitting multiple sclerosis (RRMS) discontinue treatment with disease-modifying drug (DMD) within the first year, and of the patients who do continue, about 40% are nonadherent. Shared decision making may decrease nonadherence and discontinuation rates, but evidence in the context of RRMS is limited. Shared decision making may, however, come at additional costs. This study aimed to explore the potential cost-effectiveness of shared decision making for RRMS in comparison with usual care, from a (limited) societal perspective over a lifetime. Methods An exploratory economic evaluation was conducted by adapting a previously developed state transition model that evaluates the cost-effectiveness of a range of DMDs for RRMS in comparison with the best supportive care. Three potential effects of shared decision making were explored: 1) a change in the initial DMD chosen, 2) a decrease in the patient's discontinuation in using the DMD, and 3) an increase in adherence to the DMD. One-way and probabilistic sensitivity analyses of a scenario that combined the 3 effects were conducted. Results Each effect separately and the 3 effects combined resulted in higher quality-adjusted life years (QALYs) and costs due to the increased utilization of DMD. A decrease in discontinuation of DMDs influenced the incremental cost-effectiveness ratio (ICER) most. The combined scenario resulted in an ICER of euro17,875 per QALY gained. The ICER was sensitive to changes in several parameters. Conclusion This study suggests that shared decision making for DMDs could potentially be cost-effective, especially if shared decision making would help to decrease treatment discontinuation. Our results, however, may depend on the assumed effects on treatment choice, persistence, and adherence, which are actually largely unknown

Pembrolizumab for Treating Relapsed or Refractory Classical Hodgkin Lymphoma:An Evidence Review Group Perspective of a NICE Single Technology Appraisal

As part of its Single Technology Appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer (Merck Sharp & Dohme; MSD) of pembrolizumab (Keytruda (R)) to submit evidence of its clinical and cost effectiveness for the treatment of patients with relapsed or refractory classical Hodgkin lymphoma (RRcHL) who did not respond to treatment with brentuximab vedotin. Kleijnen Systematic Reviews Ltd, in collaboration with Maastricht University Medical Centre+, was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a detailed review of the evidence for the clinical and cost effectiveness of the technology, based on the company's submission to NICE. According to the NICE scope, pembrolizumab was compared with single or combination chemotherapy. Comparisons were undertaken in two populations: patients who did and did not receive prior autologous stem cell transplant (autoSCT; populations 1 and 2, respectively). Despite it having been recommended by NICE in population 1 at the time the ERG received the company submission, nivolumab was not included as a comparator. No studies directly comparing pembrolizumab and its comparators were identified. One ongoing, single-arm study of the efficacy and safety of pembrolizumab (KEYNOTE-087) and one comparative observational study (Cheah et al., 2016) were used to inform the comparative effectiveness of pembrolizumab and standard of care (SoC), using indirect comparisons in both populations. Almost all analyses showed significant PFS and overall response rate benefits for pembrolizumab versus SoC, but due to being based on indirect comparison, were likely to contain systematic error. The economic evaluation therefore suffered from substantial uncertainty in any estimates of cost effectiveness. Furthermore, there was a lack of evidence on the uptake and timing of allogeneic stem cell transplant, and alternative assumptions had a significant impact on cost effectiveness. Immature survival data from KEYNOTE-087 exacerbated this issue and necessitated the use of alternative data sources for longer-term extrapolation of survival. Some issues identified in the company's analyses were amended by the ERG. The revised ERG deterministic base-case incremental cost-effectiveness ratios based on the company's second Appraisal Consultation Document response for pembrolizumab versus SoC (with a commercial access agreement) for populations 1 and 2 were 54,325 pound and 62,527 pound per quality-adjusted life-year gained, respectively. There was substantial uncertainty around these ICERs, especially in population 2. NICE did not recommend pembrolizumab as an option for treating RRcHL in population 1, but recommended pembrolizumab for use within the Cancer Drugs Fund in population 2

Nivolumab for Treating Metastatic or Unresectable Urothelial Cancer:An Evidence Review Group Perspective of a NICE Single Technology Appraisal

As part of its single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer (Bristol-Myers Squibb) of nivolumab (Opdivo (R)) to submit evidence of its clinical and cost effectiveness for metastatic or unresectable urothelial cancer. Kleijnen Systematic Reviews Ltd, in collaboration with Maastricht University Medical Centre+, was commissioned to act as the independent Evidence Review Group (ERG), which produced a detailed review of the evidence for the clinical and cost effectiveness of the technology, based on the company's submission to NICE. Nivolumab was compared with docetaxel, paclitaxel, best supportive care and retreatment with platinum-based chemotherapy (cisplatin plus gemcitabine, but only for patients whose disease has had an adequate response in first-line treatment). Two ongoing, phase I/II, single-arm studies for nivolumab were identified, but no studies directly compared nivolumab with any specified comparator. Evidence from directly examining the single arms of the trial data indicated little difference between the outcomes measured from the nivolumab and comparator studies. A simulated treatment comparison (STC) analysis was used in an attempt to reduce the bias induced by naive comparison, but there was no clear evidence that risk of bias was reduced. Multiple limitations in the STC were identified and remained. The effect of an analysis based on different combinations of covariates in the prediction model remains unknown. The ERG's concerns regarding the economic analysis included the use of a non-established response-based survival analysis method, which introduced additional uncertainty. The use of time-dependent hazard ratios produced overfitting and was not represented in the probabilistic sensitivity analysis. The use of a treatment stopping rule to cap treatment cost left treatment effectiveness unaltered. A relevant comparator was excluded from the base-case analysis. The revised ERG deterministic base-case incremental cost-effectiveness ratios based on the company's Appraisal Consultation Document response were 58,791 pound, 78,869 pound and 62,352 pound per quality-adjusted life-year gained versus paclitaxel, docetaxel and best supportive care, respectively. Nivolumab was dominated by cisplatin plus gemcitabine in the ERG base case. Substantial uncertainties about the relative treatment effectiveness comparing nivolumab against all comparators remained. NICE did not recommend nivolumab, within its marketing authorisation, as an option for treating locally advanced, unresectable or metastatic urothelial carcinoma in adults who have had platinum-containing therapy, and considered that nivolumab was not suitable for use within the Cancer Drugs Fund