PMCID: 11409488 (link)
Year: 2024
Reviewer Paper ID: 18
Project Paper ID: 74
Q1 - Title(show question description)
Explanation: The article's title explicitly states that it is an economic evaluation of the use of drug-coated balloons in a clinical setting, and it specifies the interventions being compared as part of the IN.PACT AV Access Trial.
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"IN.PACT AV Access Trial: Economic Evaluation of Drug-Coated Balloon Treatment for Dysfunctional Arteriovenous Fistulae Based on 12-Month Clinical Outcomes"
Q2 - Abstract(show question description)
Explanation: The abstract does not provide a structured summary that includes the context, key methods, results, and alternative analyses in a structured format. While it mentions the purpose, methods, and results, it lacks subheadings or a clear structure for each of these sections, and the abstract does not mention alternative analyses clearly within its format.
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The abstract does not include subheadings separating context, methods, results, or alternatives analyses.
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It describes the 'Purpose', 'Materials and Methods', 'Results', and 'Conclusions' but lacks detail on alternative analyses or a clear structured format.
Q3 - Background and objectives(show question description)
Explanation: The introduction provides a clear context for the study, discussing the challenges and costs associated with end-stage renal disease and hemodialysis in the U.S. It presents the study question by emphasizing the need to evaluate the economic consequences of using drug-coated balloons versus percutaneous transluminal angioplasty, making it relevant for decision-making in healthcare policy.
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ESRD and hemodialysis not only present a dramatic clinical and quality-of-life challenge for patients but also create significant cost to the healthcare system.
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Medicare spent more than $94,000 per year per hemodialysis patient in 2019, amounting to total annual costs of more than $37 billion for Medicare fee-for-service beneficiaries alone.
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Therefore, the objective of this study was to evaluate the long-term costs of DCBs compared with those of PTA for treating dysfunctional AVFs in the U.S. healthcare system using the IN.PACT AV balloon.
Q4 - Health economic analysis plan(show question description)
Explanation: The manuscript confirms that a health economic analysis plan was developed and mentions where relevant information, such as cost inputs and detailed methodologies, can be accessed. Specifically, it references an online source where supplemental materials related to the economic analysis are available.
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"For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules (details available online on the article's Supplemental Material page at www.jvir.org)."
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"Additional trial details have been previously published. The ethics committee or institutional review board (as appropriate for each study site) approved the IN.PACT AV Access study from which the clinical data for this analysis were obtained."
Q5 - Study population(show question description)
Explanation: The manuscript provides demographic and clinical characteristics of the study population. It includes age, sex, and specific clinical parameters observed in the trial.
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The trial randomized a total of 330 participants (n = 170 and n = 160 in the DCB and PTA groups, respectively).
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Age (y) 65.6 +- 13.3 Studies by Lookstein et al or Holden et al
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Sex (% male) 64.5% Studies by Lookstein et al or Holden et al
Q6 - Setting and location(show question description)
Explanation: The manuscript provides relevant contextual information, notably about the setting and location, which is critical to understanding the study's economic implications. The analysis is conducted from a U.S. healthcare perspective, specifically considering costs from a U.S. payer (Medicare) standpoint, and emphasizes the economic burden and setting of AV fistula treatments in the U.S.
Quotes:
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To study, from a U.S. payer's perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae.
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In 2019, more than 500,000 patients with end-stage renal disease (ESRD) required hemodialysis in the United States.
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The first analysis used the mean absolute number of trial-observed access circuit reinterventions through 12 months and projected treatment outcomes to 3 years, using the U.S. Medicare perspective for costs and 12-month clinical results for outcomes.
Q7 - Comparators(show question description)
Explanation: The manuscript provides a detailed description of the interventions being compared, specifically the drug-coated balloon (DCB) and standard percutaneous transluminal angioplasty (PTA) used in the treatment of dysfunctional hemodialysis arteriovenous fistulae. Moreover, it includes the rationale for their selection by citing the need for more effective and cost-saving therapies to manage the high costs associated with vascular access in hemodialysis patients.
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In the IN.PACT AV Access study, percutaneous transluminal angioplasty (PTA) with drug-coated balloons (DCBs) was recently shown to be superior to PTA with a standard uncoated, non-high-pressure PTA in treating dysfunctional AVFs.
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Therefore, the objective of this study was to evaluate the long-term costs of DCBs compared with those of PTA for treating dysfunctional AVFs in the U.S. healthcare system using the IN.PACT AV balloon.
Q8 - Perspective(show question description)
Explanation: The study adopted a U.S. payer's perspective, specifically focusing on Medicare, for the economic evaluation of drug-coated balloons versus standard percutaneous transluminal angioplasty in treating stenotic lesions in dysfunctional arteriovenous fistulae. This perspective was likely chosen to assess the financial impact on the U.S. healthcare system, given Medicare's significant expenditure on hemodialysis patients, as demonstrated by the substantial costs associated with AV fistula maintenance.
Quotes:
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To study, from a U.S. payer's perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae.
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This study and the underlying IN.PACT AV Access study were sponsored by Medtronic. Cost differences between the DCB and PTA strategies were estimated via 2 different analyses, both using the U.S. Medicare perspective for costs and the 12-month clinical results for outcomes.
Q9 - Time horizon(show question description)
Explanation: The time horizon for the study is projected up to 36 months, which is appropriate as it allows for the evaluation of longer-term economic outcomes of drug-coated balloons (DCBs) versus percutaneous transluminal angioplasty (PTA) beyond the clinical trial data collected at 12 months. This extended time frame helps in assessing the potential cost savings and clinical benefits over a substantial period following initial treatment.
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The first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months and projected treatment outcomes to 3 years.
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The first analysis yielded a projected 3-year cost saving of $4,263 for the DCB strategy.
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For subsequent model cycles up to the analysis horizon of 36 months, the participants who were alive were assumed to have a reintervention rate that resembled the year 1 events.
Q10 - Discount rate(show question description)
Explanation: The manuscript specifies a discount rate of 3% per annum, chosen based on recommendations from the U.S. Panel on Cost-Effectiveness and the American College of Cardiology/American Heart Association statement, to ensure consistency with standard practices in economic evaluations.
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All costs were discounted at 3% per annum, in line with recommendations promulgated by the U.S. Panel on Cost-Effectiveness and the relevant American College of Cardiology/American Heart Association statement.
Q11 - Selection of outcomes(show question description)
Explanation: The manuscript uses the number of access circuit reinterventions and access circuit primary patency rates as measures of benefit and harm. These metrics directly impact cost and resource utilization, making them pivotal in the economic evaluation of DCB vs PTA.
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For the purposes of the present economic analyses, this study focused on the reintervention events and ACPP as the clinical outcomes because they are both directly associated with treatment cost and resource utilization.
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The primary effectiveness measure was the target lesion primary patency rate through 6 months, defined as freedom from clinically driven target lesion revascularization or access circuit thrombosis.
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Using the absolute number of access circuit reinterventions approach, the DCB strategy resulted in an estimated per-patient savings...
Q12 - Measurement of outcomes(show question description)
Explanation: The outcomes used to capture benefits and harms, such as reintervention events and access circuit primary patency, were measured and detailed using clinical data from the IN.PACT AV Access study. The study focused on reintervention rates and patency as indicators directly associated with treatment cost and resource utilization, projecting costs and clinical outcomes over several years.
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'For the purposes of the present economic analyses, this study focused on the reintervention events and ACPP as the clinical outcomes because they are both directly associated with treatment cost and resource utilization.'
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'The primary effectiveness measure was the target lesion primary patency rate through 6 months, defined as freedom from clinically driven target lesion revascularization or access circuit thrombosis measured through 6 months after the procedure.'
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'The first analysis yielded a projected 3-year cost saving of $4,263 for the DCB strategy on the basis of a projected cumulative reduction of 1.06 reinterventions (1.70 for DCB vs 2.76 for PTA) over the analysis horizon.'
Q13 - Valuation of outcomes(show question description)
Explanation: The manuscript describes methods used to measure and value outcomes, focusing on a randomized clinical trial with 330 participants for the IN.PACT AV Access study. The outcomes were measured using trial-observed reintervention rates and access circuit primary patency rates over 12 months. Valuation involved Medicare cost models and a decision-analytic model projecting costs over up to 3 years.
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'The trial randomized a total of 330 participants (n = 170 and n = 160 in the DCB and PTA groups, respectively).'
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'The first analysis used a decision-analytic model that included "postendovascular intervention" and "death" as its 2 health states.'
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'For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules.'
Q14 - Measurement and valuation of resources and costs(show question description)
Explanation: The costs in this study were valued from a U.S. Medicare perspective. The analysis used Medicare reimbursement amounts to estimate the total treatment costs for DCB and PTA strategies, considering the index procedure costs and access circuit reintervention costs. They employed fiscal year 2020 Medicare fee schedules for cost calculations and considered site-of-service distributions for a weighted average of payments.
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The first analysis used the reintervention rates from the clinical trial and the applicable Medicare reimbursement amounts, projecting costs through 3 years of follow-up.
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For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules.
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A weighted average of payment was estimated for the base case calculations on the basis of the Medicare site-of-service distribution (calendar year 2018 data).
Q15 - Currency, price, date, and conversion(show question description)
Explanation: The manuscript clearly states the dates for resource quantities and unit costs and specifies the currency and year for conversion in the methods section. It uses the fiscal year 2020 Medicare fee schedules for costs and inflates costs using the medical consumer price index to 2019 U.S. dollars.
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For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules (details available online on the article's Supplemental Material page at www.jvir.org).
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All costs were inflated from 2013 to 2019 dollars using the medical consumer price index.
Q16 - Rationale and description of model(show question description)
Explanation: The manuscript describes in detail the decision-analytic model used in the first analysis, providing a rationale for its use in evaluating cost differences over a 3-year horizon. Furthermore, the manuscript indicates that the model and additional materials, such as cost inputs, are available in the supplemental materials online at the journal's website.
Quotes:
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The first analysis used a decision-analytic model that included "postendovascular intervention" and "death" as its 2 health states.
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For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules (details available online on the article's Supplemental Material page at www.jvir.org).
Q17 - Analytics and assumptions(show question description)
Explanation: The manuscript provides details on the methods for analyzing and statistically transforming the data, extrapolation, and model validation used in the study. Analytical models, assumptions about mortality and clinical event rates, and cost projections were all clearly described alongside the use of specific statistical tools and software.
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The first analysis used a decision-analytic model that included 'postendovascular intervention' and 'death' as its 2 health states.
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Analyses were performed using Stata MP15 (StataCorp, College Station, Texas), JMP 15 (SAS Institute, Cary, North Carolina), and TreeAge Pro (TreeAge LLC, Williamstown, Massachusetts).
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Uncertainty in the number of access circuit reinterventions at 12 months, projected clinical events, and cost projections were additionally explored by plotting the calculated 95% CIs on the basis of the reported 12-month clinical data and evaluating significance.
Q18 - Characterizing heterogeneity(show question description)
Explanation: The manuscript describes cost analyses and event rate projections but does not specify methods to estimate result variations for different sub-groups in terms of characteristics such as age, sex, or severity of disease condition, which are typically used as subgroup analyses.
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The results section, discussion, and methods emphasize cost analysis and savings rather than subgroup differences: 'The cost difference between the DCB and PTA strategies at 36 months was the main economic outcome.'
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Scenario and Sensitivity Analyses discussed overall cost differences but did not outline specific sub-group variations beyond broad scenario analyses, such as 'analyses based on the variation of sex, age, and mortality hazard ratio.'
Q19 - Characterizing distributional effects(show question description)
Explanation: The manuscript does not explicitly address the distribution of impacts across different individuals, nor does it mention adjustments made specifically to reflect priority populations. The focus is on the economic evaluation of treatments without detailing population characteristics or priority adjustments.
Quotes:
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This study and the underlying IN.PACT AV Access study were sponsored by Medtronic. Cost differences between the DCB and PTA strategies were estimated via 2 different analyses, both using the U.S. Medicare perspective for costs and the 12-month clinical results for outcomes.
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Scenario analyses included a decreased or lower relative clinical effectiveness in years 2 and 3; variation in the 12-month event rates; analyses based on the variation of sex, age, and mortality hazard ratio; as well as scenarios exploring the implication of potential additional payment for DCB devices.
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Third, although the analysis uses national average cost inputs, some regional differences may exist in specific geographies.
Q20 - Characterizing uncertainty(show question description)
Explanation: The manuscript describes various methods to characterize uncertainty in the analysis, including sensitivity analyses with different scenarios and assumptions regarding clinical effectiveness and costs. This includes exploring the implications of varying reintervention rates, incremental benefits, and DCB costs.
Quotes:
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'Respective access circuit reintervention events were accounted for in each model cycle. Monthly reintervention events were modeled on the basis of the event rates observed at 6 and 12 months. For subsequent model cycles up to the analysis horizon of 36 months, the participants who were alive were assumed to have a reintervention rate that resembled the year 1 events, with other effectiveness scenarios:reflecting uncertainty in the 1-year data and derived projections:being explored in extensive sensitivity analyses, including a diminishing DCB effect and fewer reintervention events with PTA.'
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'Scenario analyses included a decreased or lower relative clinical effectiveness in years 2 and 3; variation in the 12-month event rates; analyses based on the variation of sex, age, and mortality hazard ratio; as well as scenarios exploring the implication of potential additional payment for DCB devices.'
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'Uncertainty in the number of access circuit reinterventions at 12 months, projected clinical events, and cost projections were additionally explored by plotting the calculated 95% CIs on the basis of the reported 12-month clinical data and evaluating significance.'
Q21 - Approach to engagement with patients and others affected by the study(show question description)
Explanation: The manuscript does not mention any engagement or involvement of patients, service recipients, the general public, communities, or stakeholders in the design of the study. The study seems to focus primarily on economic evaluations and clinical outcomes without engaging these groups in the study's design process.
Quotes:
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This study and the underlying IN.PACT AV Access study were sponsored by Medtronic.
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Clinical data and resource utilization for the DCB and PTA strategies were obtained from the 12-month data of the IN.PACT AV Access study.
Q22 - Study parameters(show question description)
Explanation: The manuscript comprehensively presents analytic inputs, study parameters, and assumptions in the methods and results sections, including details on cost assumptions, event rates, and sensitivity analyses exploring uncertainties. The tables and figures further detail these inputs, their sources, and the assumptions underlying the analysis.
Quotes:
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For reinterventions, details about the use of balloon procedures, stent procedures, and thrombectomy procedures were obtained from the trial data. In addition, the number of DCB catheters used in the DCB index procedure, the frequency of required surgical reinterventions, and the use of duplex ultrasound examinations in each strategy were captured.
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The cost difference at 2.5 years of follow-up was calculated on the basis of the annualized cost by Thamer et al as well as the 1-year cost difference based on their reported 1-year costs. All costs were inflated from 2013 to 2019 dollars using the medical consumer price index.
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Scenario analyses included a decreased or lower relative clinical effectiveness in years 2 and 3; variation in the 12-month event rates; analyses based on the variation of sex, age, and mortality hazard ratio; as well as scenarios exploring the implication of potential additional payment for DCB devices.
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Similar mortality rates were observed for the DCB and PTA at 12 months in the IN.PACT AV Access study; therefore, no survival difference between the 2 strategies was assumed.
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The CIs of events and costs did not overlap, indicating statistically significant differences (P < .025) (Fig 1; Supplemental Figure E2, available online at www.jvir.org).
Q23 - Summary of main results(show question description)
Explanation: The mean values for the main categories of costs and outcomes were indeed reported and summarized in an appropriate measure. The manuscript provides detailed results on cost savings achieved using DCB, presented in mean values and associated statistical measures, across different analysis methods.
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The first analysis yielded a projected 3-year cost saving of $4,263 for the DCB strategy...Savings accumulated over time, with projected 1- and 2-year per-patient savings of $1,632 and $3,038, respectively.
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The second analysis, based on a bootstrapped dataset, found a mean 12-month cost of $12,207 (95% CI, $11,751-$12,656) per patient for the DCB strategy and a mean 12-month cost of $14,359 (95% CI, $13,807-$14,818) per patient for the PTA strategy.
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The mean cost difference was $2,152 (P < .0001)...the mean costs were $24,722 (95% CI, $23,418-$25,671) and $28,615 (95% CI, $27,654-$29,906) for DCB and PTA strategies, respectively.
Q24 - Effect of uncertainty(show question description)
Explanation: The manuscript discusses how uncertainty about assumptions and inputs affected findings. It describes sensitivity analyses that explored varying clinical performance assumptions and cost inputs, including changes in discount rates and time horizons. The effects of these variables on cost savings were evaluated, making it clear that the authors considered such uncertainties and reported their impact on the findings.
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Uncertainty in the number of access circuit reinterventions at 12 months, projected clinical events, and cost projections were additionally explored by plotting the calculated 95% CIs on the basis of the reported 12-month clinical data and evaluating significance.
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All costs were discounted at 3% per annum, in line with recommendations promulgated by the U.S. Panel on Cost-Effectiveness and the relevant American College of Cardiology/American Heart Association statement.
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The extensive sensitivity analyses document the effect of differing assumptions about longer-term effectiveness.
Q25 - Effect of engagement with patients and others affected by the study(show question description)
Explanation: The manuscript does not provide any evidence or mention of involvement from patients, service recipients, the general public, community, or other stakeholders in the design, approach, or findings of the study. The focus is on economic analysis and clinical data from the IN.PACT AV Access study, without reference to external involvement.
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In the IN.PACT AV Access study, percutaneous transluminal angioplasty (PTA) with drug-coated balloons (DCBs) was recently shown to be superior to PTA with a standard uncoated, non-high-pressure PTA in treating dysfunctional AVFs. In that study, DCBs had a higher target lesion primary patency than PTA through 6 months...
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This study and the underlying IN.PACT AV Access study were sponsored by Medtronic. Cost differences between the DCB and PTA strategies were estimated via 2 different analyses, both using the U.S. Medicare perspective for costs and the 12-month clinical results for outcomes.
Q26 - Study findings, limitations, generalizability, and current knowledge(show questiondescription)
Explanation: The manuscript does not contain details regarding ethical or equity considerations related to the study, nor does it mention the potential impact of the findings on patients, policy, or practice explicitly. The focus is predominantly on economic evaluations and cost savings associated with the use of drug-coated balloons compared to standard treatments for dysfunctional arteriovenous fistulae.
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"This study and the underlying IN.PACT AV Access study were sponsored by Medtronic."
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"First, a multiyear projection was performed on the basis of the 1-year trial data. However, it is a requirement for health-economic analyses to explore the potential effect of interventions beyond the follow-up data collected in a trial."
SECTION: TITLE
IN.PACT AV Access Trial: Economic Evaluation of Drug-Coated Balloon Treatment for Dysfunctional Arteriovenous Fistulae Based on 12-Month Clinical Outcomes
SECTION: ABSTRACT
Purpose:
To study, from a U.S. payer's perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae. hemodialysis arteriovenous fistulae.
Materials and Methods:
Cost differences between DCBs and PTA at year 1 and beyond were calculated via 2 methods. The first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months (0.65 +- 1.05 vs 1.05 +- 1.18 events perThe first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months (0.65 +- 1.05 vs 1.05 +- 1.18 events per patient for DCBs and PTA, respectively) and projected treatment outcomes to 3 years. The second approach was based on the trial-observed access circuit primary patency rates at 12 months (53.8% vs 32.4%) and calculated the cost difference on the basis of previously published Medicare cost for patients who maintained or did not maintain primary patency. Assumptions regarding DCB device prices were tested in sensitivity analyses, and the numbers needed to treat were calculated.
Results:
Using the absolute number of access circuit reinterventions approach, the DCB strategy resulted in an estimated per-patient savings of $1,632 at 1 year and $4,263 at 3 years before considering the DCB device cost. The access circuit primary patency approach was associated with a per-patient cost savings of $2,152 at 1 year and $3,894 at 2.5 years of follow-up. At the theoretical DCB device reimbursement of $1,800, savings were $1,680 and $2,049 at 2.5 and 3 years, respectively. The one-year NNT of DCB compared to PTA was 2.48.
Conclusions:
Endovascular therapy for arteriovenous access stenosis with the IN.PACT AV DCB can be expected to be cost-saving if longer follow-up data confirm its clinical effectiveness.
SECTION: INTRO
In 2019, more than 500,000 patients with end-stage renal disease (ESRD) required hemodialysis in the United States. ESRD and hemodialysis not only present a dramatic clinical and quality-of-life challenge for patients but also create significant cost to the healthcare system. Medicare spent more than $94,000 per year per hemodialysis patient in 2019, amounting to total annual costs of more than $37 billion for Medicare fee-for-service beneficiaries alone. Approximately 65% of patients on hemodialysis with prevalent ESRD use an arteriovenous (AV) fistula (AVF) for vascular access. The costs associated with creating and maintaining vascular access required for hemodialysis comprise a sizable share of these annual costs and highlight the need for advances in treatment to improve outcomes and reduce costs. Over the last few years, several trials of new balloon-based and stent graft-based treatments for AVF stenosis have been conducted, including the IN.PACT AV Access study.
In the IN.PACT AV Access study, percutaneous transluminal angioplasty (PTA) with drug-coated balloons (DCBs) was recently shown to be superior to PTA with a standard uncoated, non-high-pressure PTA in treating dysfunctional AVFs. In that study, DCBs had a higher target lesion primary patency than PTA through 6 months (82.2% vs 59.5%; absolute risk difference 22.8%, with a 95% confidence interval (CI) of 12.8%-32.8%). The 12-month clinical outcomes have been reported in this issue of Journal of Vascular and Interventional Radiology. However, not much is known about the economic consequences of DCB use in this clinical indication.
Therefore, the objective of this study was to evaluate the long-term costs of DCBs compared with those of PTA for treating dysfunctional AVFs in the U.S. healthcare system using the IN.PACT AV balloon.
SECTION: METHODS
MATERIALS AND METHODS
Overview
This study and the underlying IN.PACT AV Access study were sponsored by Medtronic.This study and the underlying IN.PACT AV Access study were sponsored by Medtronic. Cost differences between the DCB and PTA strategies were estimated via 2 different analyses, both using the U.S. Medicare perspective for costs and the 12-month clinical results for outcomes.This study and the underlying IN.PACT AV Access study were sponsored by Medtronic. Cost differences between the DCB and PTA strategies were estimated via 2 different analyses, both using the U.S. Medicare perspective for costs and the 12-month clinical results for outcomes. In the first analysis, the DCB- and PTA-specific total treatment costs (including index procedure and access circuit reinterventions) were calculated using the reintervention rates from the clinical trial and the applicable Medicare reimbursement amounts, projecting costs through 3 years of follow-up. In the second analysis, the cost difference between the DCB and PTA strategies was calculated on the basis of the trial-observed 12-month access circuit primary patency (ACPP) rates and previously published AVaccess-related costs over 2.5 years in Medicare beneficiaries, associated with maintained versus lost primary patency. In addition, the number needed to treat (NNT) was calculated. Because no separate reimbursement exists for DCBs, the base case did not consider incremental device costs. However, scenario calculations were performed, exploring the effect of added cost to payers for the use of DCB devices.
Study Data
Analysis inputs are shown in Table 1. Clinical data and resource utilization for the DCB and PTA strategies were obtained from the 12-month data of the IN.PACT AV Access study. In brief, this was a prospective multicenter randomized clinical trial that evaluated the IN.PACT AV DCB (Medtronic Inc., Santa Rosa, California) versus PTA in participants with de novo or nonstented restenotic lesions up to 100 mm in length in AV dialysis fistulae. The trial randomized a total of 330 participants (n = 170 and n = 160 in the DCB and PTA groups, respectively). The primary safety endpoint was the rate of serious adverse events involving the AV access circuit through 30 days after the procedure. The primary effectiveness measure was the target lesion primary patency rate through 6 months, defined as freedom from clinically driven target lesion revascularization or access circuit thrombosis measured through 6 months after the procedure. Additional trial details have been previously published. The ethics committee or institutional review board (as appropriate for each study site) approved the IN.PACT AV Access study from which the clinical data for this analysis were obtained.
For the purposes of the present economic analyses, this study focused on the reintervention events and ACPP as the clinical outcomes because they are both directly associated with treatment cost and resource utilization. For reinterventions, details about the use of balloon procedures, stent procedures, and thrombectomy procedures were obtained from the trial data. In addition, the number of DCB catheters used in the DCB index procedure, the frequency of required surgical reinterventions, and the use of duplex ultrasound examinations in each strategy were captured.
For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules
For the first analysis, costs were based on the fiscal year 2020 Medicare fee schedulesFor the first analysis, costs were based on the fiscal year 2020 Medicare fee schedules (details available online on the article's Supplemental Material page at www.jvir.org). Because AVF interventions are performed in different settings of care:physician office, ambulatory surgery center (ASC), and hospital inpatient and outpatient settings:a weighted average of payment was estimated for the base case calculations on the basis of the Medicare site-of-service distribution (calendar year 2018 data). The costs of surgical reinterventions were determined on the basis of the types of surgical reinterventions performed and the corresponding Medicare payments. Duplex ultrasound costs were included only if performed in the office setting because they are not separately reimbursed in other settings.
For the second analytic approach, the previously reported vascular access costs from Thamer et al for participants who had maintained versus those who had not maintained AVF primary patency at 12-month follow-up were used because that cohort ("cohort 1") most closely resembled the current study population.
Model-Based Projections and Analysis Scenarios
The first analysis used a decision-analytic model that included "postendovascular intervention" and "death" as its 2 health states.The first analysis used a decision-analytic model that included "postendovascular intervention" and "death" as its 2 health states. Participants in the modeled cohorts progressed through these states on the basis of strategy-specific event rates, with a modeled cycle length of 1 month. Respective access circuit reintervention events were accounted for in each model cycle. Monthly reintervention events were modeled on the basis of the event rates observed at 6 and 12 months. For analysis purposes, the current study assumed the reported 6-month events to be equally distributed in that 6-month period. The same assumption was made for the incremental events in the subsequent 6-month period leading up to the reported 12-month data point. For subsequent model cycles up to the analysis horizon of 36 months, the participants who were alive were assumed to have a reintervention rate that resembled the year 1 events, with other effectiveness scenarios:reflecting uncertainty in the 1-year data and derived projections:being explored in extensive sensitivity analyses, including a diminishing DCB effect and fewer reintervention events with PTA. Furthermore, in addition to the weighted average cost across the different sites of care, costs were reported separately for each site of service.
Similar mortality rates were observed for the DCB and PTA at 12 months in the IN.PACT AV Access study; therefore, no survival difference between the 2 strategies was assumed. For survival projections, the age- and sex-matched mortality rates from U.S. life tables were used. These were adjusted through a hazard ratio to match the trial-observed mortality.
The cost difference between the DCB and PTA strategies at 36 months was the main economic outcome. Shorter analysis horizons were explored in the sensitivity analyses. All costs were discounted at 3% per annum, in line with recommendations promulgated by the U.S. Panel on Cost-Effectiveness and the relevant American College of Cardiology/American Heart Association statement.t Association statement. Scenario analyses included a decreased or lower relative clinical effectiveness in years 2 and 3; variation in the 12-month event rates; analyses based on the variation of sex, age, and mortality hazard ratio; as well as scenarios exploring the implication of potential additional payment for DCB devices.Scenario analyses included a decreased or lower relative clinical effectiveness in years 2 and 3; variation in the 12-month event rates; analyses based on the variation of sex, age, and mortality hazard ratio; as well as scenarios exploring the implication of potential additional payment for DCB devices.. Uncertainty in the number of access circuit reinterventions at 12 months, projected clinical events, and cost projections were additionally explored by plotting the calculated 95% CIs on the basis of the reported 12-month clinical data and evaluating significance.Uncertainty in the number of access circuit reinterventions at 12 months, projected clinical events, and cost projections were additionally explored by plotting the calculated 95% CIs on the basis of the reported 12-month clinical data and evaluating significance.
The second analysis did not require a projection or analysis model because the cost difference between the 2 strategies could be calculated directly from the trial-observed 12-month ACPP rates for DCB and PTA and the vascular access cost data by Thamer et al. The cost difference at 2.5 years of follow-up was calculated on the basis of the annualized cost by Thamer et al as well as the 1-year cost difference based on their reported 1-year costs. All costs were inflated from 2013 to 2019 dollars using the medical consumer price index. Trial-derived primary patency for each group and the annual costs for primary patency versus nonpatency were resampled 5,000 times; the total 1-year and 2.5-year costs were compared using the Wilcoxon rank sum test given nonnormally distributed data.
Additional analyses included the calculation of costs per reintervention avoided based on cost data from the main analysis and observed/projected reintervention events. Similarly, the NNT to avoid 1 reintervention was calculated on the basis of these event data.
Analyses were performed using Stata MP15 (StataCorp, College Station, Texas), JMP 15 (SAS Institute, Cary, North Carolina), and TreeAge Pro (TreeAge LLC, Williamstown, Massachusetts).
SECTION: RESULTS
RESULTS
The first analysis yielded a projected 3-year cost saving of $4,263 for the DCB strategy on the basis of a projected cumulative reduction of 1.06 reinterventions (1.70 for DCB vs 2.76 for PTA) over the analysis horizon. Savings accumulated over time, with projected 1- and 2-year per-patient savings of $1,632 and $3,038, respectively. The CIs of events and costs did not overlap, indicating statistically significant differences (P .025) (Fig 1; Supplemental Figure E2, available online at www.jvir.org).
The second analysis, based on a bootstrapped dataset, found a mean 12-month cost of $12,207 (95% CI, $11,751-$12,656) per patient for the DCB strategy and a mean 12-month cost of $14,359 (95% CI, $13,807-$14,818) per patient for the PTA strategy. The mean cost difference was $2,152 (P .0001). For the 30-month horizon, the mean costs were $24,722 (95% CI, $23,418-$25,671) and $28,615 (95% CI, $27,654-$29,906) for DCB and PTA strategies, respectively, with a mean cost difference of $3,893 (P .0001) (Fig 2; Supplemental Figure E3, available online at www.jvir.org).
Scenario and Sensitivity Analyses
Performing site-of-service-specific calculations of the first analysis, as opposed to the blended scenario, resulted in the following projected cost savings over the 3-year horizon: $1,925 for the physician office setting, $3,066 for the ASC setting, $6,095 for the hospital outpatient setting, and $21,307 for the hospital inpatient setting. Cost savings at shorter analysis horizons are included in Figure E1 (available online at www.jvir.org).
The effects of changes in clinical and cost assumptions on cost difference between the strategies and on the cumulative difference in projected event rates at 3 years in the first analysis are shown in Table 2. Without the consideration of additional device payment for the DCB strategy, DCBs remained cost saving across all the studied scenarios and at all time frames between 1 and 3 years. Savings were more pronounced with longer follow-up. Hypothetical additional payment for DCBs, between $1,800 and $2,200 per device, led to smaller cost savings at 3 years. A payment of $1,800 per DCB device:based on manufacturer-provided list price:led to approximate cost neutrality between 1 and 2 years but was associated with higher incremental cost for the DCB strategy at 1 year. The use of 1 device per procedure, as opposed to the 1.23 devices assumed in the base case, would lead to more pronounced savings.
NNT, Budget Impact, and Threshold Analysis
The NNT to avoid 1 reintervention over a 1-year period was 2.48. Under constant event rate assumptions beyond 1 year, the NNT was reduced to 1.34 over a 2-year horizon and to 0.94 over a 3-year horizon.
Under the assumption that 50% of the current approximately 233,000 annual access circuit PTA procedures would be performed with DCBs instead of PTA, Medicare could expect to save between $190 million (based on the first analysis) and $250 million (based on the second analysis) per year. Over 3 years, potential savings are projected to be approximately $497 million on the basis of the first analysis.
Considering a 2.5-year analysis horizon, it was projected that Medicare could expect cost savings as long as the potential additional payment for DCBs is lower than $2,820 or $3,165 per device based on the 2 analyses, respectively.
SECTION: DISCUSS
DISCUSSION
Using 2 different analytic approaches, this study explored the economic consequences of DCB use instead of PTA in the treatment of dysfunctional AVFs. The clinical effectiveness improvement documented through 12 months in the IN.PACTAV Access study was found to be associated with a meaningful savings potential to Medicare. The first:main:analysis required assumptions about DCB effectiveness beyond the currently available trial follow-up, whereas the second analysis facilitated projections through 2.5 years based on actual trial-demonstrated ACPP rates at 1 year.
Both analyses:despite taking different analytic approaches:found directionally similar cost differences of more than $3,800 at follow-up between 2.5 and 3 years. These projected cost savings for Medicare will be lowered by any incresmental payment for DCB therapy. To assess the implications of such added costs, several hypothetical scenarios were explored and found that DCBs remain cost saving at 2.5 and 3 years for costs up to $2,800 per device.
There are significant differences in reimbursement by site of service for dialysis access maintenance using angioplasty with PTA (with or without DCB). In 2018, approximately 50% of all angioplasty procedures for dialysis access maintenance were performed in the physician office setting for a payment of $1,300 per procedure. In 2018, reimbursement was higher in other settings: $2,142 in the ASC setting (19% of angioplasty procedures), $4,953 for outpatient treatment in hospitals (26% of angioplasty procedures), and $20,841 for hospital inpatient treatment (4% of angioplasty procedures). The site-of-service-specific analyses of this study found substantial variation in projected Medicare savings and may provide useful additional information for policy makers and providers because therapy adoption and potential reimbursement scenarios were considered (Supplemental Figure E1, available online at www.jvir.org). Based on past experiences with DCB reimbursement for the treatment of the femoropopliteal artery, patient access to DCBs in a physician office setting is expected to be limited if not nonexistent because of the steep reimbursement barrier. It remains to be seen whether appropriate reimbursement mechanisms are implemented that balance the projected savings to Medicare with the added device cost that providers would incur if they adopt DCBs as the more efficacious clinical strategy and without which Medicare would not be able to experience the full extent of the savings.
The projection in the first analysis assumed that event rates beyond 12 months would be similar to those observed in the first year. This assumption for the base case was chosen as a "middle-of-the-road" estimate in light of conflicting evidence available from prior studies. In a retrospective single-center study of 720 patients with AVF, the clinical effectiveness of repeated percutaneous intervention diminished with each successive procedure. This suggests an increasing reintervention burden over time. At the same time, evidence from the 144 participants in the PTA group of the recent Lutonix AV Randomized Trial suggests a somewhat lower number of reinterventions needed to maintain target lesion primary patency in the second year than in the first year. The scenario analyses performed in this study provide insight into the implication of changes in the clinical performance assumptions. In this context, it is noteworthy that the second analysis, which relied only on trial-observed 12-month primary patency rates without any further assumptions, found cost savings for DCB that were slightly higher than the savings projected in the first analysis, providing some assurance that the assumptions in this (main) analysis were reasonable.
The findings of the current study are directionally in line with a prior European study evaluating the clinical effectiveness and cost effectiveness of DCB use for the treatment of AVF failure. Kitrou et al performed a cost-effectiveness analysis on the basis of a single-institution randomized controlled trial comparing participants treated with DCB or PTA (n = 20 in each group). They found DCBs to be associated with cost savings and outcome improvement, which justified the added cost of DCBs in a European context.
The reintervention cost in the main analysis, with an estimated 1-year cost for index plus reintervention procedures of approximately $5,500-$6,800, is lower than the total vascular access costs documented in prior studies. For example, the previously referenced study by Nordyke et al found vascular access costs in the first and second year to amount to $14,526 and $6,444, respectively (in 2017 U.S. dollars). Similarly, the study by Thamer et al used in the second analysis found the first year costs of $6,442 for patients who maintained primary patency and $15,009 for patients who lost patency, followed by $4,279 and $7,402, respectively, in the second year. This, again, suggests that the cost difference in the main analysis of the current study, relying only on reintervention cost, may be conservative. On the other hand, the significant downward trend in access-related costs between years 1 and 2 observed by both Nordyke et al and Thamer et al suggests that in the immediate months following AVF creation, higher costs are incurred that are tied to complications other than those requiring endovascular reintervention. In turn, this suggests that the vascular access costs in the second year may be more closely related to reintervention costs, which would explain the closer resemblance with the costs found in this study's main analysis.
Among the strengths of the current analysis is its reliance on clinical data from a contemporary and independently adjudicated randomized controlled trial. Furthermore, the approach to pursue 2 independent analytic approaches:one of them relying on current fee schedules and the other on a previously published analysis of Medicare costs for patients maintaining or not maintaining ACPP at 1 year:led to very similar calculated cost differences.
At the same time, the analysis is subject to several limitations. First, a multiyear projection was performed on the basis of the 1-year trial data. However, it is a requirement for health-economic analyses to explore the potential effect of interventions beyond the follow-up data collected in a trial. This is particularly important when the intervention can be expected to have additional clinical benefit beyond the current follow-up period. The extensive sensitivity analyses document the effect of differing assumptions about longer-term effectiveness. Second, this analysis was based on cost to Medicare as the primary payer, evaluated on the basis of reimbursement amounts paid by Medicare, as opposed to a detailed microcosting performed alongside the trial. However, the analysis perspective in this study was the payer perspective, with the primary objective to evaluate the cost implications to Medicare. Third, although the analysis uses national average cost inputs, some regional differences may exist in specific geographies. Fourth, on this basis, this analysis is also more limited than a full cost-utility analysis that would also estimate differences in quality-adjusted life year (QALY) gain. Considering no observed mortality difference at 12 months, it is safe to assume that any QALY gain between the 2 strategies could be expected to be derived from a lower reintervention burden. For example, in the IN.PACT SFA study, a QALY decrement of 0.06 QALYs was calculated to be associated with each target lesion revascularization. Finally, the findings of this study are based on data from the IN.PACT AVAccess study and may, therefore, not apply to other DCB devices and to cohorts whose characteristics and treatment approaches differ from those of the IN.PACT AV Access study.
In summary, the treatment of AVFs with the IN.PACT AV DCB may lead to substantive per-patient and health system savings with concurrent improvement in patient outcome. This analysis should be updated when longer-term follow-up data from the pivotal trial become available.
SECTION: SUPPL
Supplementary Material
Figures E1-E3 and Tables E1 and E2 can be found by accessing the online version of this article on www.jvir.org and selecting the Supplemental Material tab.
SECTION: ABBR
ABBREVIATIONS
ACPP
access circuit primary patency
ASC
ambulatory surgery center
AV
arteriovenous
AVF
arteriovenous fistula
CI
confidence interval
DCB
drug-coated balloon
ESRD
end-stage renal disease
NNT
number needed to treat
PTA
percutaneous transluminal angioplasty
QALY
quality-adjusted life year
SECTION: FIG
Projected cumulative access circuit reintervention events and costs for percutaneous transluminal angioplasty (PTA) and drug-coated balloons (DCBs) through 36 months. (a) Projected cumulative access circuit reintervention events and (b) resulting cumulative per-patient costs for PTA and DCB through 36 months. Six- and 12-month clinical events as observed in the IN.PACT AV Access study; subsequent clinical events projected assuming that the event rates and treatment effect observed at 1 year are maintained. The 95% confidence interval (CI) calculated on the basis of 12-month clinical event rates. Note: These payer costs do not take into account any DCB device reimbursement because there is currently no incremental payment for the use of DCB.
Trial-observed 12-month access circuit primary patency and projected 12- and 30-month total vascular access costs. Resulting per-patient cost differences are shown between percutaneous transluminal angioplasty (PTA) and drug-coated balloons (DCBs) at 12 and 30 months.
SECTION: TABLE
Analysis Inputs
Variable Definition Source Clinical parameters Age (y) 65.6 +- 13.3 Studies by Lookstein et al or Holden et al Sex (% male) 64.5% Studies by Lookstein et al or Holden et al Mortality HR of persons with ESRD on hemodialysis, relative to general population mortality 6.75 Calibrated on the basis of the pooled mortality estimate at 12 mo as reported in the study by Falk et al. Effectiveness: access circuit reintervention events PTA, at 6 mo 0.65 +- 0.8 Study by Lookstein et al. DCB, at 6 mo 0.32 +- 0.7 Study by Lookstein et al. Difference in access circuit reintervention events at 6 mo -0.33 (P .001) Study by Lookstein et al. PTA, at 12 mo 1.05 +- 1.18 Study by Holden et al. DCB, at 12 mo 0.65 +- 1.05 Study by Holden et al. Difference in access circuit reintervention events at 12 mo -0.40 (P .001) Study by Holden et al. Effectiveness: access circuit primary patency PTA, 12 mo 32.4% Study by Holden et al. DCB, 12 mo 53.8% Study by Holden et al. Difference in access circuit primary patency at 12 mo 21.4%. (P .001) Study by Holden et al. Use of devices per respective reintervention procedure (full details inTables E1 and E2) DCB 1.23 Use in the IN.PACT AV Access trial, post hoc analysis. BMS (used in 10% of reinterventions) 1.0 Use in the IN.PACT AV Access trial, post hoc analysis. Cost parameters: first (main) analysis Medicare fee schedule amounts, weighted average PTA procedure cost $3,332 Weighted average of Medicare calendar year 2020 payments, considering the following site-of-service mix: 51%, physician office; 26%, hospital outpatient; 19%, ambulatory surgery center; and 4%, hospital inpatient. Respective site-of-service amounts reflect national average payment (details shown in Supplemental Materials). DCB procedure cost $3,332 (+DCB additional payment where explored) Same as PTA procedure cost (base case), plus additional DCB costs (scenario analyses). Reintervention cost $4,113 Weighted average payments as described earlier, assuming 85% PTA, 10% stent placement, and 5% thrombectomies and surgical interventions as observed in the trial (details shown in Supplemental Materials). Cost parameters: second analysis Vascular access cost in year 1 for patients who maintained access circuit primary patency at 12 mo after AVF creation $7,561 Study by Abdel-Kader et al, inflated from 2013 to 2019 U.S. dollars using the medical consumer price index. Vascular access cost in year 1 for patients who lost primary patency at 12 mo after AVF creation $17,617 Study by Abdel-Kader et al, inflated from 2013 to 2019 U.S. dollars using the medical consumer price index. Vascular access cost over 2.5 years for patients who maintained primary patency at 12 mo after AVF creation $16,315 Calculated on the basis of the annualized cost reported in the study by Abdel-Kader et al, inflated from 2013 to 2019 U.S. dollars using the medical consumer price index. Vascular access cost over 2.5 years for patients who lost access circuit primary patency at 12 mo after AVF creation $34,511 Calculated on the basis of the annualized cost reported in the study by Abdel-Kader et al, inflated from 2013 to 2019 U.S. dollars using the medical consumer price index. Discounting Discount rate on costs, p.a. 3.0% Recommendations of the Panel on Cost-Effectiveness analysis.
AVF = arteriovenous fistula; BMS = bare-metal stent; DCB = drug-coated balloon; ESRD = end-stage renal disease; HR = hazard ratio; p.a. = annually; PTA = percutaneous transluminal angioplasty.
Scenario and Sensitivity Analyses: Cost Difference for DCB startegy versus PTA Strategy at Years 1, 2, and 3 and Projected Difference in Cumulative Reintervention Events at 3 Years
Scenario Cost difference DCB vs PTA ($) Three-year difference in cumulative reintervention events 1 y 2 y 3 y 3 y with $1,800 DCB cost considered Base case -1,632 -3,038 -4,263 -2,049 -1.06 Mortality HR 8.0 (3-y survival, 69%) -1,621 -2,986 -4,151 -1,937 -1.03 Mortality HR 5.0 (3-y survival, 80%) -1,648 -3,113 -4,426 -2,212 -1.10 Age 53 (1 standard deviation below the mean) -1,669 -3,208 -4,637 -2,423 -1.14 Age 79 (1 standard deviation above the mean) -1,487 -2,404 -2,977 -763 -0.77 100% male -1,623 -2,993 -4,166 -1,952 -1.04 100% female -1,650 -3,120 -4,441 -2,227 -1.10 No incremental benefit for DCB beyond year 2 -1,632 -3,038 -3,078 -864 -0.75 No incremental benefit for DCB beyond year 1 -1,632 -1,678 -1,718 496 -0.40 PTA events in years 2 and 3 10% lower than the first year, DCB events 10% higher than the first year -1,632 -2,466 -3,192 -978 -0.78 PTA events in years 2 and 3 15% lower than the first year, DCB events 15% higher than the first year -1,632 -2,179 -2,656 -442 -0.64 PTA events in years 2 and 3 20% lower than the first year, DCB events 20% higher than the first year -1,632 -1,893 -2,120 94 -0.51 Additional incremental benefit for DCB in years 2 and 3 (0.50 annual events instead of 0.65) -1,632 -3,535 -5,192 -2,978 -1.30 Revascularization events in years 2 and 3 at 80% of their respective first-year values -1,632 -2,766 -3,754 -1,540 -0.93 Revascularization events in years 2 and 3 at 80% and 60% of their respective first-year values -1,632 -2,766 -3,517 -1,303 -0.87 Revascularization events in years 2 and 3 at 120% of their respective first-year values -1,632 -3,310 -4,772 -2,558 -1.19 Cost undiscounted -1,651 -3,122 -4,442 -2,228 -1.06 Cost discounted at 5% p.a. -1,620 -2,986 -4,153 -1,939 -1.06 Additional payment for DCB $1,800 (and use of 1.23 DCB devices per procedure) 582 -824 -2,049 N/A (see left) -1.06 Additional payment for DCB $2,000 (and use of 1.23 DCB devices per procedure) 828 -578 -1,803 N/A (see left) -1.06 Additional payment for DCB $2,200 (and use of 1.23 DCB devices per procedure) 1,074 -332 -1,557 N/A (see left) -1.06 Additional payment for DCB $1,800 (and use of 1.0 DCB devices per procedure) 168 -1,238 -2,463 N/A (see left) -1.06 Additional payment for DCB $2,000 (and use of 1.0 DCB devices per procedure) 368 -1,038 -2,263 N/A (see left) -1.06 Additional payment for DCB $2,200 (and use of 1.0 DCB devices per procedure) 568 -838 -2,063 N/A (see left) -1.06
Note-Analyses refer to the main analysis.
DCB = drug-coated balloon angioplasty; HR = hazard ratio; p.a. = annually; PTA = percutaneous transluminal angioplasty.