Coronary artery bypass graft surgery: clinical decision making and cost-effectiveness analysis

Trends in the cost-effectiveness level of percutaneous coronary intervention: Macro socioeconomic analysis and health technology assessment

Percutaneous coronary intervention (PCI), one of the most prevalent techniques of revascularization, is a procedure that remarkably improves treatment outcomes. However, it consumes large amounts of medical resources and has resulted in an increased socioeconomic burden due to the increasing number of target patients. In recent years, there have been sporadic discussions, both in Japan and other countries, regarding the optimization of interventions and the perspective of medical economics. Based on this, previous studies on PCI-related cost-effectiveness were reviewed in order to consider the current level of medical economics regarding PCI. Using the databases MEDLINE and EMBASE, a survey involving data from original articles and systematic reviews was conducted from January 2010 to August 2022. Conditions were not imposed on the evidence level due to the paucity of studies, although field studies were prioritized over simulation studies. The macro medical economics of acute myocardial infarction treatment, which is the primary target of PCI, were generally at an average level when compared to those in other countries; however, there is room for further improvement in Japan's performance. Revascularization in a population with multivessel coronary artery disease showed that coronary artery bypass graft surgery tended to be more cost-effective than PCI in the long-term setting. However, it was suggested that PCI may be more cost-effective in patients with SYNTAX Score ≤22 or left main artery disease. A cost-effectiveness report for stable angina patients was not in favor of PCI over medical therapy. Moreover, there were some reports showing the medical economic superiority of early myocardial ischemia evaluation, and it was foreseen that active selection of patients will contribute to the improvement of the overall cost-effectiveness of PCI. In order to further improve the socioeconomic significance of PCI in the future, it is necessary to aim for harmony between clinical practice and health economics.

Advances in Quantitative Techniques for Making Medical Decisions

Articles relating decision theory to medical problems have appeared in the medical literature over the past thirtyyears. Mostof the work important to recent advances has been performed in the past 10 to 15 years. We describe the progress which occurred between 1978 and 1988: an increased acceptance of quantitative approaches, advances in analytical techniques, simplification of older methods to enhance accessibility, and a better understanding of the interface between methods that prescribe how decisions should be made and those that describe how decisions actually are made. We also discuss problems that have not been overcome and those which reflect the "growing pains" of success, including increased scrutiny by non-methodologist medical content experts.

Optimizing Value From Cardiac Rehabilitation: A Cost-Utility Analysis Comparing Age, Sex, and Clinical Subgroups

OBJECTIVE

To assess the cost utility of a center-based outpatient cardiac rehabilitation program compared with no program within patient subgroups on the basis of age, sex, and clinical presentation (acute coronary syndrome [ACS] or non-ACS).

METHODS

We performed a cost-utility analysis from a health system payer perspective to compare cardiac rehabilitation with no cardiac rehabilitation for patients who had a cardiac catheterization. The Markov model was stratified by clinical presentation, age, and sex. Clinical, quality-of-life, and cost data were provided by the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and TotalCardiology.

RESULTS

The incremental cost per quality-adjusted life-year (QALY) gained for cardiac rehabilitation varies by subgroup, from $18,101 per QALY gained to $104,518 per QALY gained. There is uncertainty in the estimates due to uncertainty in the clinical effectiveness of cardiac rehabilitation. Overall, the probabilistic sensitivity analysis found that 75% of the time participation in cardiac rehabilitation is more expensive but more effective than not participating in cardiac rehabilitation.

CONCLUSION

The cost-effectiveness of cardiac rehabilitation varies depending on patient characteristics. The current analysis indicates that cardiac rehabilitation is most cost effective for those with an ACS and those who are at higher risk for subsequent cardiac events. The findings of the current study provide insight into who may benefit most from cardiac rehabilitation, with important implications for patient referral patterns.

Coronary artery bypass grafting: Part 1--the evolution over the first 50 years

Surgical treatment for angina pectoris was first proposed in 1899. Decades of experimental surgery for coronary artery disease finally led to the introduction of coronary artery bypass grafting (CABG) in 1964. Now that we are approaching 50 years of CABG experience, it is appropriate to summarize the advancement of CABG into a procedure that is safe and efficient. This review provides a historical recapitulation of experimental surgery, the evolution of the surgical techniques and the utilization of CABG. Furthermore, data on contemporary clinical outcomes are discussed.

A forensic evaluation of the National Emphysema Treatment Trial using the expected value of information approach

BACKGROUND/RATIONALE

Expected value of information (EVI) analyses allow researchers to estimate the returns to conducting research. We used EVI techniques to estimate the value of the National Emphysema Treatment Trial (NETT), a multicenter randomized trial of lung-volume-reduction surgery (LVRS) versus medical therapy (MT) for patients with severe emphysema, then compared that result to the trial cost.

METHODS

We gathered information on costs and benefits of LVRS and MT before the trial and the costs of conducting the NETT, and compared these data with the results of the cost-effectiveness analysis conducted alongside the trial. We used 2 thresholds to represent the societal value of a quality-adjusted life year (QALY): USD 50,000 and USD100,000.

RESULTS

The cost effectiveness of LVRS versus MT using historical (nontrial) information was USD 305,000/QALY. Based on these data and the threshold incremental cost-effectiveness ratio values, the expected value of perfect information was USD 46 million and USD 670 million for thresholds USD 50,000 and USD 100,000 per QALY, respectively. The NETT was powered for 1,250 patients in each arm; ultimately approximately 600 patients in each arm were recruited. With 1,250 patients per arm, the expected value of sample information was USD 660 million for the threshold of USD100,000. The actual cost of the NETT was approximately USD 60 million. The expected net benefit of sampling was USD 600 million.

CONCLUSIONS

Given the difference between the cost of the trial and the economic benefits of the information, the EVI analyses suggest that federal investment in the NETT trial represented good value for money.

Economic evaluation of sirolimus-eluting stents

BACKGROUND

Sirolimus-eluting stents have recently been shown to reduce the risk of restenosis among patients who undergo percutaneous coronary intervention (PCI). Given that sirolimus-eluting stents cost about 4 times as much as conventional stents, and considering the volume of PCI procedures, the decision to use sirolimus-eluting stents has large economic implications.

METHODS

We performed an economic evaluation comparing treatment with sirolimus-eluting and conventional stents in patients undergoing PCI and in subgroups based on age and diabetes mellitus status. The probabilities of transition between clinical states and estimates of resource use and health-related quality of life were derived from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. Information on effectiveness was based on a meta-analysis of randomized controlled clinical trials (RCTs) comparing sirolimus-eluting and conventional stents.

RESULTS

Cost per quality-adjusted life year (QALY) gained in the baseline analysis was Can58,721 dollars. Sirolimus-eluting stents were more cost-effective in patients with diabetes and in those over 75 years of age, the costs per QALY gained being 44,135 dollars and 40,129 dollars, respectively. The results were sensitive to plausible variations in the cost of stents, the estimate of the effectiveness of sirolimus-eluting stents and the assumption that sirolimus-eluting stents would prevent the need for cardiac catheterizations in the subsequent year when no revascularization procedure was performed to treat restenosis.

INTERPRETATION

The use of sirolimus-eluting stents is associated with a cost per QALY that is similar to or higher than that of other accepted medical forms of therapy and is associated with a significant incremental cost. Sirolimus-eluting stents are more economically attractive for patients who are at higher risk of restenosis or at a high risk of death if a second revascularization procedure were to be required.

Role of clopidogrel in unstable angina and non-ST-segment elevation myocardial infarction: from literature and guidelines to practice

Clinical trials are the backbone of treatment paradigm shifts and guideline development. In terms of acute coronary syndromes, the American College of Cardiology and the American Heart Association (ACC-AHA) have developed extensive guidelines to assist the practitioner in the appropriate use of drugs including antiischemic, anticoagulant, and antiplatelet agents. Clopidogrel, an adenosine 5'-diphosphate antagonist, is one such drug. Unfortunately, consensus guidelines are limited by the design of the clinical trials they reference. Clopidogrel trials have examined various outcomes in patients for a limited time frame, making longer term use of the drug difficult to justify. An ongoing study, estimated to be completed in 2005, is evaluating the long-term use of clopidogrel in high-risk patients. Aspirin, however, has become a lifelong therapy for many patients, based on clinical trials and medical experience. Patient-specific risk factors, the drugs' safety profiles, and costs, in addition to the ACC-AHA guidelines, must all be considered by clinicians when selecting the appropriate agent and its duration of use.

Cost effectiveness of lung volume reduction surgery

Lung volume reduction surgery (LVRS) is a costly new procedure that could influence quality of life and survival for persons who have severe emphysema. This article reviews the history of LVRS from an economic and policy perspective and provides estimates of the cost effectiveness of LVRS derived from the National Emphysema Treatment Trial, a recently completed multicenter evaluation of LVRS, compared with medical care. Estimates of the potential impact of LVRS on the national health care budget are provided. The high cost and uncertainty regarding the long-term cost effectiveness of LVRS warrant further evaluation after public and private health insurers make coverage decisions for this procedure, particularly if it is adopted as part of the standard of care.

Cost effectiveness of lung-volume-reduction surgery for patients with severe emphysema

BACKGROUND

The National Emphysema Treatment Trial, a randomized clinical trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema, included a prospective economic analysis.

METHODS

After pulmonary rehabilitation, 1218 patients at 17 medical centers were randomly assigned to lung-volume-reduction surgery or continued medical treatment. Costs for the use of medical care, medications, transportation, and time spent receiving treatment were derived from Medicare claims and data from the trial. Cost effectiveness was calculated over the duration of the trial and was estimated for 10 years of follow-up with the use of modeling based on observed trends in survival, cost, and quality of life.

RESULTS

Interim analyses identified a group of patients with excess mortality and little chance of improved functional status after surgery. When these patients were excluded, the cost-effectiveness ratio for lung-volume-reduction surgery as compared with medical therapy was 190,000 dollars per quality-adjusted life-year gained at 3 years and 53,000 dollars per quality-adjusted life-year gained at 10 years. Subgroup analyses identified patients with predominantly upper-lobe emphysema and low exercise capacity after pulmonary rehabilitation who had lower mortality and better functional status than patients who received medical therapy. The cost-effectiveness ratio in this subgroup was 98,000 dollars per quality-adjusted life-year gained at 3 years and 21,000 dollars at 10 years. Bootstrap analysis revealed substantial uncertainty for the subgroup and 10-year estimates.

CONCLUSIONS

Given its cost and benefits over three years of follow-up, lung-volume-reduction surgery is costly relative to medical therapy. Although the predictions are subject to substantial uncertainty, the procedure may be cost effective if benefits can be maintained over time.

Economic evaluation of new therapies in critical illness

The recent Food and Drug Administration approval of drotrecogin alfa (activated) and the potential of several other new therapies may represent the beginning of a breakthrough in the management of critical illness in the intensive care unit. However, their use in clinical practice will likely be dependent on a rigorous appraisal not only of their effects, but also of their costs. Novel therapies can no longer be judged simply by their effectiveness in treating illness, but must also be evaluated on an institutional and societal level on the basis of their cost. These considerations have important implications for the practicing intensivist, who will need to better understand the conduct and design of economic evaluations, including their strengths and weaknesses. In this article, we review the rationale behind economic evaluations of new therapies and the alternative economic approaches available. We then discuss in more detail the elements contained in a cost-effectiveness analysis, the preferred approach to pharmacoeconomic evaluation today.

Do HEDIS measures reflect cost-effective practices?

PURPOSE

Whether the Health Plan Employer Data and Information Set (HEDIS) performance measures for managed care plans encourage a cost-effective use of society's resources has not been quantified. Our study objectives were to examine the cost-effectiveness evidence for the clinical practices underlying HEDIS 2000 measures and to develop a list of practices not reflected in HEDIS that have evidence of cost effectiveness.

DATA SOURCES

Two databases of economic evaluations (Harvard School of Public Health Cost-Utility Registry and the Health Economics Evaluation Database) and two published lists of cost-effectiveness ratios in health and medicine.

STUDY SELECTION

For each of the 15 "effectiveness of care" measures in HEDIS 2000, we searched the data through 1998 for cost-effectiveness ratios of similar interventions and target populations. We also searched for important interventions with evidence of cost-effectiveness (<$20,000 per life-year [LY] or quality-adjusted life year [QALY] gained), which are not included in HEDIS. All ratios were standardized to 1998 dollars. The data were collected and analyzed during fall 2000 to summer 2001.

DATA EXTRACTION

Cost-effectiveness ratios reporting outcomes in terms of cost/LY or cost/QALY gained were included if they matched the intervention and population covered by the HEDIS measure.

DATA SYNTHESIS

Evidence was available for 11 of the 15 HEDIS measures. Cost-effectiveness ranges from cost saving to $660,000/LY gained. There are numerous non-HEDIS interventions with some evidence of cost effectiveness, particularly interventions to promote healthy behaviors.

CONCLUSIONS

HEDIS measures generally reflect cost-effective practices; however, in a number of cases, practices may not be cost effective for certain subgroups. Data quality and availability as well as study perspective remain key challenges in judging cost effectiveness. Opportunities exist to refine existing measures and to develop additional measures, which may promote a more efficient use of societal resources, although more research is needed on whether these measures would also satisfy other desirable attributes of HEDIS.

Screening blood donations for hepatitis C in Central Africa: analysis of a risk- and cost-based decision tree

Four screening strategies (no testing, HC Abbott, HC Pasteur, and a combined test) for the detection of hepatitis C virus (HCV) antibody in donated blood were considered in a formal decision tree. Decision criteria included residual risk of infection and overall monetary cost. Tree parameters were determined using data from the Central African Republic. The prevalences observed among blood donors for HIV infection, hepatitis B, syphilis, and hepatitis C varied between 6% and 15%. The current residual risk of transfusion-transmitted infections is very high (8.4%). Screening for HCV would bring that risk down to about 3% with either the HC Pasteur, the HC Abbott, or the combined test. Even though baseline analysis gives preference to the HC Abbott test (the combined test coming out last), Monte Carlo sensitivity and uncertainty analyses showed that Abbott's and Pasteur's tests are interchangeable, on the basis or either risk or cost considerations.

Decision analysis in surgery

BACKGROUND

The technique of decision analysis is often applied to clinical policy and economic issues in surgery. Because surgeons may be unfamiliar with such work, this article catalogues decision analysis studies in the surgical specialties.

METHODS

We reviewed the medical literature (1966 to 1994) to identify surgical decision analysis studies and to assess trends over time. Each article was categorized according to the type of journal (surgical, other clinical, or technical) in which it was published and content, including surgical specialty, clinical topic, article focus (individual patient decision making, clinical policy, or cost-effectiveness), and primary findings.

RESULTS

Publication rates of surgical decision analysis have increased dramatically over time. Of the 86 total studies only six were published before 1980. In contrast, 44 studies appeared between 1990 and 1994. Although 77% were published in nonsurgical journals, decision analyses have begun to appear more regularly in surgical forums. Studies addressing all of the surgical specialties were found, although more than one half addressed topics in general surgery (34%) or cardiothoracic surgery (22%). The most frequent topics were gallstones (11 articles), head and neck cancer (five articles), coronary artery disease (four articles), and cerebral arteriovenous malformations (four articles). Articles focusing on clinical policy (i.e., those assessing surgical efficacy for broad groups of patients) now account for large majority of published decision analyses.

CONCLUSIONS

The use of decision analysis in surgery is growing steadily. Because decision analysis is being used to influence clinical policy, it is important for surgeons to be aware of these studies and to be able to review them critically.

Evaluating the potential cost-effectiveness of stenting as a treatment for symptomatic single-vessel coronary disease. Use of a decision-analytic model

BACKGROUND

Coronary stenting appears to provide more predictable immediate results and lower rates of restenosis than conventional balloon angioplasty for selected lesion types, but its hospital costs are significantly higher. This study was designed to evaluate the potential cost-effectiveness of Palmaz-Schatz coronary stenting relative to conventional balloon angioplasty for the treatment of patients with symptomatic, single-vessel coronary disease.

METHODS AND RESULTS

We developed a decision-analytic model to predict quality-adjusted life expectancy and lifetime treatment costs for patients with symptomatic, single-vessel coronary disease treated by either Palmaz-Schatz stenting (PSS) or conventional angioplasty (PTCA). Estimates of the probabilities of overall procedural success (PTCA, 97%; PSS, 98%), abrupt closure requiring emergency bypass surgery (PTCA, 1.0%; PSS, 0.6%), and angiographic restenosis (PTCA, 37%; PSS, 20%) were derived from review of the literature published as of September 1993. Procedural costs were based on the true economic (ie, variable) costs of each procedure at Boston's Beth Israel Hospital. On the basis of these data, coronary stenting was estimated to result in a higher quality-adjusted life expectancy than conventional angioplasty but to incur additional costs as well. Compared with conventional angioplasty, stenting had an estimated incremental cost-effectiveness ratio of $23,600 per quality-adjusted life year gained. Although the cost-effectiveness ratio for stenting changed with variations in assumptions about the relative costs and restenosis rates, it remained less than $40,000 per quality-adjusted year of life gained--and thus was similar to many other accepted medical treatments--unless the stent angiographic restenosis rate was > 23%, the angioplasty restenosis rate was < 34%, or the cost of stenting (including vascular complications) exceeded that of conventional angioplasty by more than $3000. The alternative strategy of secondary stenting (initial angioplasty followed by stenting only for symptomatic restenosis) was estimated to be both less effective and less cost-effective than primary stenting over a wide range of plausible assumptions and thus does not appear to be cost-effective when primary stenting is also an option.

CONCLUSIONS

Decision-analytic modeling can be used to evaluate the potential cost-effectiveness of new coronary interventions. Our analysis suggests that despite its higher cost, elective coronary stenting may be a reasonably cost-effective treatment for selected patients with single-vessel coronary disease. Primary stenting is unlikely to be cost-effective for lesions with a low probability of restenosis (eg, < 30%) or for patients for whom the cost of stenting is expected to be much higher than usual (eg, because of a high risk of vascular complications). Given the sensitivity of the cost-effectiveness ratios to even modest variations in the relative restenosis rates and cost estimates, future studies will be necessary to determine more precisely the cost-effectiveness of coronary stenting for specific patient and lesion subsets.

Fee-for-benefit: a strategy to improve the quality of health care and control costs through reimbursement incentives

OBJECTIVES

The purpose of this study was to determine whether reimbursement in direct proportion to expected therapeutic benefit is capable of improving the utilization and cost of health care.

BACKGROUND

The benefit associated with a particular medical or surgical treatment varies widely from patient to patient. Nevertheless, payment to the provider of the treatment is essentially invariant under the current fee-for-service system. Under an alternative fee-for-benefit strategy, empiric data are used to construct a multivariate model to predict the expected benefit to an individual patient from a particular health care service on the basis of conventional clinical descriptors. The payers and the providers of the service then openly negotiate an explicit economic relation between expected benefit and monetary payment such that payment is directly proportional to benefit.

METHODS

Computer simulations were performed to determine the potential impact of this fee-for-benefit strategy with respect to medical versus surgical treatment of coronary artery disease.

RESULTS

Compared with conventional fee-for-service, fee-for-benefit resulted in a 12% improvement in patient benefit (quality-adjusted survival), a 22% reduction in provider payments and a 55% increase in cost/benefit (the ratio of benefit to payment).

CONCLUSIONS

The incentives embodied in a fee-for-benefit strategy can be an effective mechanism for encouraging more appropriate health care utilization while simultaneously controlling health care costs.

Chemoprophylaxis of prosthetic joint patients during dental treatment: a decision-utility analysis

A decision-analytic model and a cost effectiveness analysis was performed on 1 million hypothetic prosthetic joint patients undergoing dental treatment, to determine the most cost-effective strategy to prevent late prosthetic joint infections. The cost per quality-adjusted life-year saved (QALY) was determined for three preventive strategies: no prophylaxis, oral penicillin, and oral cephalexin. The UCLA Pain-Walking-Function-Activity Scale was used to obtain quality-of-life adjustments (utility assessment) for the study population. Costs were derived from 70 patients hospitalized between July 1, 1982, and June 30, 1986, at the UCLA Center for Health Sciences. The most cost-effective preventive strategy was the no prophylaxis alternative ($196,500/QALY). However, by recommending a 1-day strategy of oral cephalexin only to those dental patients at high risk for late prosthetic joint infections rather than a 3-day regimen to all patients, the cost effectiveness improved from $1.1 million/QALY to $446,100/QALY while maintaining a low risk of death (0.38 deaths per 10(6) dental visits).

Parameter estimates for a QALY utility model

This paper discusses a utility model for quality adjusted life years (QALY). According to this model, the utility of Y years of survival in health state Q is bYrH(Q), where b is a scaling constant and r and H(Q) are parameters. The parameter r is shown to be interpretable as a representation of a patient's risk attitude with respect to survival duration. The parameter H(Q) represents the proportionate reduction in the utility of survival when health state Q prevails. Methods are described for estimating these parameters from the results of an individual patient utility assessment. Results are then reported for empirical estimation of parameters r and H(Q) from the preference judgments of a sample of 46 coronary artery disease patients. In this empirical study, health state Q takes on two values--survival with angina pectoris and survival free from angina pectoris. Estimated values of parameters r and H(Q) are discussed in relation to the decision analysis of coronary artery bypass graft surgery. Finally, it is argued that the model deserves consideration as a medical utility model, despite some preliminary evidence that assumptions of the model are descriptively false, because it provides a simple representation of the utility of survival duration and health quality. These aspects of health outcomes are known to be critically important in the expected utility analysis of health decisions.

Preferences for health outcomes. Comparison of assessment methods

This study compared standard gamble (SG), time trade-off (TTO), and category scaling (CS) methods for assessing preferences among hypothetical outcomes of coronary artery bypass surgery. High correlations among assessment methods, as found in some previous studies, do not assure the absence of systematic differences in rating obtained by different methods. This study used analysis of variance to test for differences among the three assessment methods. Questionnaire responses were obtained from 67 of 109 physicians participating in a postgraduate course on clinical decision making, following a lecture and workshop on utility theory. SG and CS were used to rate multivariate combinations of angina (none, moderate, and severe) and survival (0, 5, and 10 years); and SG, TTO, and CS were used to rate univariate outcomes with angina (none, moderate, and severe) for the remainder of their life expectancy. SG ratings were higher than TTO ratings, which were higher than CS ratings (p less than 0.001 for all comparisons). Multivariate responses revealed a significant interaction between angina and survival dimensions using CS, but not using SG. We conclude that these methods are not interchangeable and that differences between SG and CS require a more complex explanation than differences in attitude toward risk.