Cost-effectiveness analysis in heart disease, Part III: Ischemia, congestive heart failure, and arrhythmias

Sudden Cardiac Death: Who Is at Risk?

Sudden cardiac death (SCD) is a leading cause of death in the United States. Despite improvements in therapy, the incidence of SCD as a proportion of overall cardiovascular death remains relatively unchanged. This article aims to answer the question, "Who is at risk for SCD?" In the process, it reviews the definition, pathophysiology, epidemiology, and risk factors of SCD. Patients at risk for SCD and appropriate treatment strategies are discussed.

Economic Value and Cost-Effectiveness of Cardiac Resynchronization Therapy Among Patients With Mild Heart Failure: Projections From the REVERSE Long-Term Follow-Up

OBJECTIVES

This study investigated the cost effectiveness of early cardiac resynchronization therapy (CRT) implantation among patients with mild heart failure (HF). The differential cost effectiveness between CRT using a defibrillator (CRT-Ds) and CRT using a pacemaker (CRT-P) was also assessed.

BACKGROUND

Cardiac resynchronization has been shown to be cost effective in New York Heart Association (NYHA) functional classes III/IV but is less studied in class II HF. The incremental costs of early CRT implementation in mild HF compared with the costs potentially avoided because of delaying disease progression to advanced HF are also unknown. Finally, combined biventricular pacing and defibrillator (CRT-D) devices are more expensive than biventricular pacemakers (CRT-P), but the relative cost effectiveness is controversial.

METHODS

Data from the 5-year follow-up phase of REVERSE (REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction) were used. The economics were evaluated from the U.S. Medicare perspective based on published clinical projections.

RESULTS

Probabilistic estimates yielded $8,840/quality-adjusted life year (QALY) gained (95% confidence interval [CI]: $6,705 to $10,804/QALY gained) for CRT-ON versus CRT-OFF (i.e., programmed "ON" or "OFF" at pre-specified post-implantation timings) and $43,678/QALY gained for CRT-D versus CRT-P (95% CI: $35,164 to $53,589/QALY gained) over the patient's lifetime. Results were robust to choice of patient subgroup and alterations of ±10% to key model parameters. An "early" CRT-D class II strategy totaled $95,292 compared with $91,511 for a "late" implantation. An "early" implant offered on average 1.00 year of additional survival for $3,781, resulting in an ICER of $3,795/LY gained.

CONCLUSIONS

This study demonstrates CRT cost effectiveness in mild HF. The incremental CRT-D costs are justified by the anticipated benefits, despite increased procurement costs and shorter generator longevities. "Early" CRT-D implants have essential cost parity with "late" implants while increasing the patient's survival. (REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction [REVERSE]; NCT00271154).

Cost-effectiveness of zofenopril in patients with left ventricular systolic dysfunction after acute myocardial infarction: a post hoc analysis of SMILE-4

BACKGROUND

In SMILE-4 (the Survival of Myocardial Infarction Long-term Evaluation 4 study), zofenopril + acetylsalicylic acid (ASA) was superior to ramipril + ASA in reducing the occurrence of major cardiovascular events in patients with left ventricular dysfunction following acute myocardial infarction. The present post hoc analysis was performed to compare the cost-effectiveness of zofenopril and ramipril.

METHODS

In total, 771 patients with left ventricular dysfunction and acute myocardial infarction were randomized in a double-blind manner to receive zofenopril 60 mg/day (n = 389) or ramipril 10 mg/day (n = 382) + ASA 100 mg/day and were followed up for one year. The primary study endpoint was the one-year combined occurrence of death or hospitalization for cardiovascular causes. The economic analysis was based on evaluation of cost of medications and hospitalizations and was applied to the intention-to-treat population (n = 716). Cost data were drawn from the National Health Service databases of the European countries participating in the study. The incremental cost-effectiveness ratio was used to quantify the cost per event prevented with zofenopril versus ramipril.

RESULTS

Zofenopril significantly (P = 0.028) reduced the risk of the primary study endpoint by 30% as compared with ramipril (95% confidence interval, 4%-49%). The number needed to treat to prevent a major cardiovascular event with zofenopril was 13 less than with ramipril. The cost of drug therapies was higher with zofenopril (328.78 Euros per patient per year, n = 365) than with ramipril (165.12 Euros per patient per year, n = 351). The cost related to the occurrence of major cardiovascular events requiring hospitalization averaged 4983.64 Euros for zofenopril and 4850.01 Euros for ramipril. The incremental cost-effectiveness ratio for zofenopril versus ramipril was 2125.45 Euros per event prevented (worst and best case scenario in the sensitivity analysis was 3590.09 and 3243.96 Euros, respectively).

CONCLUSION

Zofenopril is a viable and cost-effective treatment for managing patients with left ventricular dysfunction after acute myocardial infarction.

Scaling up chronic disease prevention interventions in lower- and middle-income countries

Chronic diseases are increasingly becoming a health burden in lower- and middle-income countries, putting pressure on public health efforts to scale up interventions. This article reviews current efforts in interventions on a population and individual level. Population-level interventions include ongoing efforts to reduce smoking rates, reduce intake of salt and trans-fatty acids, and increase physical activity in increasingly sedentary populations. Individual-level interventions include control and treatment of risk factors for chronic diseases and secondary prevention. This review also discusses the barriers in interventions, particularly those specific to low- and middle-income countries. Continued discussion of proven cost-effective interventions for chronic diseases in the developing world will be useful for improving public health policy.

What are the costs of atrial fibrillation?

The costs of atrial fibrillation (AF) are linked to the general cost of managing AF patients in different health-care systems, as well as the cost of managing AF-related complications (e.g. hospitalizations and long-term complications, such as stroke). In addition, indirect medical costs, such as care for patients who do not recuperate fully from a vascular event, and non-medical costs such as loss of work force add to the costs of AF. All estimations for cost of AF and cost of AF therapy are based on assumptions and markedly influenced by these cost determinants. This urges for extreme caution not to take cost estimates at their absolute values. In fact, even relative comparisons between interventions may have different consequences in terms of direct and indirect costs in different health-care settings. While newer therapeutic options appear to increase the cost of AF management, newer antithrombotic substances and adequate rhythm control therapy also carry the promise of preventing the two major drivers of AF-related cost, hospitalizations and AF-related complications. Formal assessment of the cost of AF requires adjustment to local practice, and more data are clearly needed especially from primary care to better estimate the 'real' cost impact of AF.

Cost of atrial fibrillation in United States managed care organizations

INTRODUCTION

Atrial fibrillation (AF) has been shown to be associated with high healthcare costs; however, limited data are available from large-scale studies quantifying the overall cost burden of AF in the USA. We therefore aimed to provide an up to date estimate of the overall per-patient costs of AF in managed care organizations across the USA.

METHODS

This retrospective cohort study used claims data from the Integrated Healthcare Information Systems National Managed Care Benchmark Database from January 2005 to December 2006. Patients included in the analysis were aged > or =20 years and had at least two outpatient AF-related claims without hospitalization, or a hospitalization with a primary or secondary discharge diagnosis of AF in 2005. AF-related inpatient and outpatient costs over 12 months from the initial outpatient claim or first hospitalization were examined. For secondary AF hospitalizations, incremental costs associated with AF were measured by comparing costs for patients with AF with a group of matched controls hospitalized without AF.

RESULTS

In total, 35,255 patients diagnosed as having AF (5008 with a primary AF diagnosis, 10,776 with a secondary AF diagnosis, 19,471 with outpatient-managed AF), and 20,571 controls without AF, were included in the analysis. Over 12 months, for primary AF hospitalization patients, inpatient costs were $11,306.53 and outpatient costs were $2826.78 (total $14,133.30) per patient. For hospitalized patients with secondary AF, incremental AF-related inpatient costs were $5181.19 and outpatient costs were $1376.33 (total $6557.52). For AF patients with outpatient management in 2005, 12-month AF-related costs were $2177.30 ($175.47 for AF hospitalizations in 2006 and $2001.85 for outpatient costs).

CONCLUSIONS

Overall costs of AF in the US managed care organizations are high. Costs are primarily due to inpatient expenses. Improved disease management strategies to reduce AF-related hospitalizations and decrease the overall cost burden of AF are needed.

Costs and effectiveness of cardiac rehabilitation for dialysis patients following coronary bypass

Dialysis patients have a high risk of cardiovascular disease. Cardiac rehabilitation is recommended in the general population as a standard component of care and covered by Medicare for those who have undergone coronary artery bypass grafting (CABG). Here we determined the impact of cardiac rehabilitation on Medicare expenditures and its cost effectiveness in dialysis patients. A cohort of 4,324 patients with end-stage renal disease who began chronic hemodialysis and had undergone CABG over a seven year period were selected from the United States Renal Data System. Cardiac rehabilitation was defined by Current Procedural Terminology codes for monitored and non-monitored exercise in Medicare claims data. Medicare expenditures included in and outpatient claims adjusted to 1998 dollars. Over a 42-month follow-up, cardiac rehabilitation at baseline was associated with higher cumulative Medicare expenditures but this increase was not statistically significant. During the same period, cardiac rehabilitation was significantly associated with longer cumulative life, having an incremental benefit of 76 days. The incremental cost-effectiveness ratio of $13,887 per year of life saved suggests that cardiac rehabilitation is highly cost-effective in patients with end-stage renal disease following CABG.

A review of health care models for coronary heart disease interventions

This article reviews models for the treatment of coronary heart disease (CHD). Whereas most of the models described were developed to assess the cost effectiveness of different treatment strategies, other models have also been used to extrapolate clinical trials, for capacity and resource planning, or to predict the future population with heart disease. In this paper we investigate the use of modelling techniques in relation to different types of health intervention, and we discuss the assumptions and limitations of these approaches. Many of the models reviewed in this paper use decision tree models for acute or short term interventions, and Markov or state transition models for chronic or long term interventions. Discrete event simulation has, however, been used for more complex whole system models, and for modelling resource-constrained interventions and operational planning. Nearly all of the studies in our review used cohort-based models rather than population based models, and therefore few models could estimate the likely total costs and benefits for a population group. Most studies used de novo purpose built models consisting of only a small number of health states. Models of the whole disease system were less common. The model descriptions were often incomplete. We recommend that the reporting of model structure, assumptions and input parameters is more explicit, to reduce the risk of biased reporting and ensure greater confidence in the model results.

Assessing the direct costs of treating nonvalvular atrial fibrillation in the United States

OBJECTIVE

To determine the health-care resource use and costs attributable to treating atrial fibrillation (AF) in the United States.

METHODS

Retrospective analyses of three federally funded US databases (2001 data): 1) hospital inpatient stays (the Healthcare Cost and Utilization Project [HCUP]); 2) physician office visits (the National Ambulatory Medical Care Survey [NAMCS]); and 3) emergency department (ED) and hospital outpatient department visits (OPD) (the National Hospital Ambulatory Medical Care Survey [NHAMCS]). Identification of AF medical encounters was based on occurrence of AF-specific International Classification of Diseases (9th Edition)--Clinical Modification (ICD-9-CM) diagnosis code 427.31 (principal discharge diagnosis for inpatient setting; any diagnosis field for other settings). For the 10 most common principal discharge diagnoses in the inpatient setting, case-control comparison analyses were performed to estimate annual incremental costs of AF as a comorbid discharge diagnosis for hospital stays. Regression models were used to assess the impact of AF on hospitalization costs. Costs were estimated in year 2005 US dollars.

RESULTS

Approximately 350,000 hospitalizations, 5.0 million office visits, 276,000 ED visits, and 234,000 OPD were attributable to AF annually within the United States. Total annual costs for treatment of AF were estimated at $6.65 billion, including $2.93 billion (44%) for hospitalizations with a principal discharge diagnosis of AF, $1.95 billion (29%) for the incremental inpatient cost of AF as a comorbid diagnosis, $1.53 billion (23%) for outpatient treatment of AF, and $235 million (4%) for prescription drugs. In all regressions, AF was a significant contributor to hospital cost.

CONCLUSIONS

Treatment of AF represents a significant health-care burden with the costs of treating AF in the inpatient setting outweighing the costs of treating AF in the office, emergency room or hospital outpatient settings. Further research is needed to fully capture the costs of treating AF.

ICD Therapy for the Prevention of Sudden Cardiac Death in Post-MI Patients

Implantable cardioverter-defibrillators (ICDs) are unequivocally the treatment of choice for patients who have already experienced a near-fatal tachyarrhythmic event. Recently, studies have conclusively demonstrated that extending the benefits of ICD therapy to postinfarction patients with resultant left ventricular dysfunction results in dramatic additional lifesaving without the need for complex risk- stratification procedures. The landmark Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) shows that patients with reduced left ventricular function (ejection fraction < 30%) 1 month after a myocardial infarction should receive an ICD to prevent sudden cardiac death.

Cardioverter-defibrillators after MADIT-II: the balance between weight of evidence and treatment costs

The possibility of using implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden death in selected high-risk patients has prompted a series of prospective controlled studies. Recently, the MADIT II study highlighted the possibility of effective primary prevention of sudden death in patients with coronary artery disease selected by straightforward clinical data and without expensive screening (electrophysiological study). For patients with previous myocardial infarction and low left ventricular ejection fraction (</=30%), ICD implantation may reduce mortality risk by approximately 31% in the following 2 years. Implementation of this therapeutic strategy threatens to impact on public health-care spending. Possible cost-limiting mechanisms include price cuts because of increasing usage (market forces); identification of subgroups at higher risk of sudden death and use of cheaper devices with limited diagnostic and therapeutic options. Further long-term evaluation of the cost-effectiveness and cost-utility of ICDs should identify subgroups of patients for whom implantation is affordable despite current economic constraints. For heart failure patients, randomized controlled trials are currently evaluating the effects on overall survival of both conventional ICDs and devices with biventricular pacing capabilities. In this perspective, data from the COMPANION trial are expected to stimulate the use of devices with defibrillation back-up in candidates for biventricular pacing.

The economics of smoking and cardiovascular disease

The direct medical cost of cardiovascular and circulatory diseases was $151 billion in 1995, approximately 17% of all direct medical care costs in the United States. Incidence and prevalence based estimates indicate that smoking is a major contributing factor for cardiovascular disease and associated costs. Statewide smoking control programs and workplace and public area smoking bans are effective in reducing smoking prevalence. Smoking cessation therapies are very cost-effective interventions for the prevention of cardiovascular disease. Incidence based estimates indicate that smoking cessation control expenditures in the United States have been a cost effective method for reducing the direct medical costs of cardiovascular disease in the past, and may be cost saving in the future. The expected cost of producing an additional ex-smoker has been estimated to be approximately $1,000 to $1,500. Most or all of this cost can be recovered in the short run from savings in avoided heart attacks and strokes alone in healthy quitters. Observational studies of the direct medical costs following cessation in those observed to quit show a reduction utilization, but which may occur only after a lag of three to five years.

How cost-effective are new preventive strategies for cardiovascular disease?

Costs of providing a particular medical service can be measured, but it is more difficult to assess whether the service provides good value for the money spent. Rigorous trials have demonstrated the health benefits connected with interventions for treatment and prevention of cardiovascular disease (CVD), and in-depth analyses of the costs associated with many of those interventions have been performed. Careful use of terminology clearly differentiating among cost-minimization (relative costs of proved equivalent therapeutics), cost-effectiveness (lives saved or years of life added), and cost-benefit (total net effect in monetary terms) analyses is warranted. Although trials commonly assess clinical effectiveness as reductions in mortality or CVD-specific outcomes, improvement in quality of life may be equally important and is expressed in quality-adjusted life-years. Comparisons between therapies can be assessed as a cost-effectiveness ratio. Extensive cost-effectiveness studies have been conducted on many important cardiovascular therapies: (1) beta-blockers and diuretics for multiple CVD outcomes, mortality, and prevention of recurrent myocardial infarction (MI); (2) statins for both primary and secondary prevention of CVD; (3) enalapril for prevention and treatment of congestive heart failure; (4) tissue plasminogen activator treatment of acute MI; (5) coronary artery bypass graft for left main, single-, and 2-vessel coronary artery disease, or severe angina; (6) physician counseling for smoking; and (7) radiofrequency ablation therapy for Wolff-Parkinson-White syndrome. Therapies considered economically attractive include (1) secondary prevention with statins in hyperlipidemia, (2) smoking cessation programs, (3) primary prevention in treatment of high blood pressure with diuretics and beta-blockers, (4) primary prevention with regular exercise programs, (5) secondary prevention with cardiac rehabilitation, and (6) postinfarction treatment with beta-blockers and angiotensin-converting enzyme (ACE) inhibitors. A recent cost-minimization analysis has been performed showing aspirin to be a "best buy" therapy for secondary prevention of CVD. The Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) and Telmisartan Randomized Assessment Study in ACE-I Intolerant Patients with Cardiovascular Disease (TRANSCEND) program provide potential opportunities for both cost-minimization and cost-effectiveness analyses.

Costs and benefits of carotid endarterectomy and associated preoperative arterial imaging: a systematic review of health economic literature

BACKGROUND AND PURPOSE

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with severe stenosis of the internal carotid artery. However, the cost implications of this procedure have not yet been satisfactorily addressed. The objective of this systematic review was to critically appraise the studies addressing the economic implications of CEA and the associated preoperative arterial imaging.

METHODS

A systematic search strategy was developed to identify research articles related to the economic evaluation of CEA and the associated preoperative imaging. MEDLINE, EMBASE, and BIOSIS were electronically searched, and reference lists from identified studies were searched manually. Methods used to critically appraise these studies followed proposed guidelines for an economic evaluation that addresses 10 distinct aspects under 3 separate headings.

RESULTS

Studies identified were either partial economic or full economic evaluations, with the majority coming from the United States. The methodological quality seems to have improved over time. The studies that assessed cost-effectiveness of CEA were all modeling studies; although the same baseline parameters were used, divergent conclusions were reached. Variation in the cost estimates of CEA ($9500 to $11 500) in the same health care system was also observed in the studies reporting only on the cost of carotid surgery. For a symptomatic patient, the benefit of CEA ranged from 0.35 quality adjusted life years (QALYs) (4.2 months) at a cost of $4100 per QALY to 0.93 QALYs (11.2 months) at a cost of $434 per QALY. For an asymptomatic patient, the cost-effectiveness of CEA varied from 0.15 QALYs (1.8 months) at a cost of $52 700 per QALY to 0.25 QALYs (3 months) at a cost of $8004 per QALY.

CONCLUSIONS

Divergent conclusions of the cost-effectiveness of CEA were reported from studies that addressed the same questions and using similar parameters in their models. The cost estimates of the procedure and the different time periods used in the studies might explain these inconsistencies. Modeling studies in hypothetical cohorts might also be to blame. The cost-effectiveness of CEA will only definitively be assessed when real patient data are used.

Pharmacoeconomic considerations in assessing and selecting congestive heart failure therapies

Over the last two decades the incidence of congestive heart failure (CHF) has increased with aging of the population and in spite of the decline in age-adjusted mortality rates due to coronary heart disease. Its management has seen substantial progress, embodied in the introduction of ACE inhibitors, initially as part of triple therapy in which they complemented diuretics and digoxin, and latterly as first-line therapy. The current consensus on treatment of CHF has been based on the multiple clinical studies performed with ACE inhibitors in which these agents have been shown to prevent a new cardiovascular accident and/or progression to more severe CHF in an increasingly wide range of patients with symptomatic CHF or post-infarction left ventricular dysfunction (ejection fraction </= 40% in some trials or </= 35% in others). Not only have the results shown a marked decrease in all-cause (and especially cardiovascular) mortality, but also a great number of cost-effectiveness analyses have shown the advantages of ACE inhibitors in terms of resource allocation: they are either cost saving or convincingly cost effective compared with standard treatment with digoxin and diuretics. Other drugs require similar cost and clinical analyses before they can earn their place in an add-on strategy. To date, cost savings have been documented only for beta-blockers; implantable devices are still undergoing assessment. Two trends are now competing: one is to downplay add-on strategies and to recommend first-line therapy with ACE inhibitors and beta-blockers at effective doses, supplemented by a raft of non-pharmaceutical measures (specialist nurses, patient education, dietary advice, exercise) in a multidisciplinary approach to CHF; the second is, on the contrary, to prescribe up to five drugs for patients with advanced CHF. The evidence that this decreases hospital admission rates and patient cost is more than anecdotal, but conclusive proof of cost effectiveness is still lacking and the approach presupposes dedicated structures. This review argues that despite technical limitations, a combined approach of CHF therapy based on clinical trials and cost-effectiveness analyses is essential. However, improvements can be made. The absence of sufficient comparative data still makes it difficult to choose between drugs within the same class; institutional purchasers need to conduct such analyses to identify the drugs best suited to their patients' profiles and budgetary constraints.

Geographic differences in implantable cardioverter defibrillator usage

Despite the demonstrated efficacy of implantable cardioverter defibrillators (ICDs) in reducing sudden and total mortality in selected patients, their implantation rates vary greatly among countries. In the United States, the implantation rate is 185 implants per million inhabitants compared with only 31 implants per million in western Europe. The differences in ICD use may be explained by the following factors: manner in which sudden cardiac death is perceived by politicians and physicians (sudden cardiac death is perceived as a "nice way of dying"); differences in indications; physicians' information; prevalence of coronary artery disease; sudden cardiac death survival rates; perceived reliability of alternative treatment (namely, antiarrhythmics including amiodarone); economic backgrounds; and health care politics. Furthermore, the cost of this treatment strategy must be considered. This issue has been raised because generalization of ICD use in patients matching clinical characteristics of patients enrolled in the primary prevention trials may represent a significant economic burden to be added to the already overloaded health care system. This low acceptance may not be entirely related to budget constraint but also to the perceived efficacy of ICDs by physicians and health authorities.

Effect of clinical risk stratification on cost-effectiveness of the implantable cardioverter-defibrillator: the Canadian implantable defibrillator study

BACKGROUND

Three randomized clinical trials showed that implantable cardioverter-defibrillators (ICDs) reduce the risk of death in survivors of ventricular tachyarrhythmias, but the cost per year of life gained is high. A substudy of the Canadian Implantable Defibrillator Study (CIDS) showed that 3 clinical factors, age >/=70 years, left ventricular ejection fraction </=35%, and New York Heart Association class III, predicted the risk of death and benefit from the ICD. We estimated the extent to which selecting patients for ICD therapy based on these risk factors makes ICD therapy more economically attractive.

METHODS AND RESULTS

Patients in CIDS were grouped according to whether they had >/=2 of 3 risk factors. Incremental cost-effectiveness of ICD therapy was computed as the ratio of the difference in mean cost to the difference in life expectancy between the 2 groups. Over 6.3 years, the mean cost per patient in the ICD group was Canadian (C) $87 715 versus $38 600 in the amiodarone group (C$1 approximately US$0.67). Life expectancy for the ICD group was 4.58 years versus 4.35 years for amiodarone, for an incremental cost-effectiveness of ICD therapy of C$213 543 per life-year gained. The cost per life-year gained in patients with >/=2 factors was C$65 195, compared with C$916 659 with <2 risk factors.

CONCLUSIONS

The cost-effectiveness of ICD therapy varies by patient risk factor status. The use of ICD therapy in patients who have >/=2 risk factors of age >/=70 years, left ventricular ejection fraction </=35%, and NYHA class III is C$65 195 to gain a year of life.

Evidence rather than costs must guide use of the implantable cardioverter defibrillator

Randomized controlled trials have shown superior survival rates with implantable cardioverter defibrillators (ICDs) compared with antiarrhythmic drugs in survivors of cardiac arrest and life-threatening ventricular tachyarrhythmias, as well as in high-risk patients with ischemic heart disease and inducible ventricular tachycardia (VT). Current defibrillators are small and implanted with techniques similar to standard pacemakers. They provide high-energy shocks for ventricular fibrillation (VF) and rapid VT, antitachycardia pacing for monomorphic VT, and antibradycardia pacing. Limited evidence suggests that ICD therapy is cost-effective when compared with other widely accepted treatments. The use of ICDs is likely to continue to expand in the future. Ongoing clinical trials will define further prophylactic indications of the ICD and clarify its cost-effectiveness ratio in different clinical settings.

One thousand health-related quality-of-life estimates

OBJECTIVE

Analysts performing cost-effectiveness analyses often do not have the resources to gather original quality-of-life (QOL) weights. Furthermore, variability in QOL for the same health state hampers the comparability of cost-effectiveness analyses. For these reasons, opinion leaders such as the Panel on Cost-Effectiveness in Health and Medicine have called for a national repository of QOL weights. Some authors have responded to the call by performing large primary studies of QOL. We take a different approach, amassing existing data with the hope that it will be combined responsibly in meta-analytic fashion. Toward the goal of developing a national repository of QOL weights to aid cost-effectiveness analysts, 1,000 health-related QOL estimates were gathered from publicly available source documents.

METHODS

To identify documents, we searched databases and reviewed the bibliographies of articles, books, and government reports. From each document, we extracted information on the health state, QOL weight, assessment method, respondents, and upper and lower bounds of the QOL scale. Detailed guidelines were followed to ensure consistency in data extraction.

RESULTS

We identified 154 documents yielding 1,000 original QOL weights. There was considerable variation in the weights assessed by different authors for the same health state. Methods also varied: 51% of authors used direct elicitation (standard gamble, time tradeoff, or rating scale), 32% estimated QOL based on their own expertise or that of others, and 17% used health status instruments.

CONCLUSIONS

This comprehensive review of QOL data should lead to more consistent use of QOL weights and thus more comparable cost-effectiveness analyses.

Economic outcomes of implantable cardioverter-defibrillators

BACKGROUND

We reviewed the literature pertaining to the cost-effectiveness of implantable cardioverter-defibrillator (ICD) therapy in the management of ventricular fibrillation and tachycardia. Discussed are the methodology, advantages, and limitations of economic-outcomes analyses as related to ICD therapy; the impact of new technology and physician practice patterns; and methodological recommendations for future studies.

METHODS AND RESULTS

Articles published between 1990 and 1997 were screened for cost-effectiveness analyses of ICD versus antiarrhythmic drug therapy. Randomized clinical trials, prospective and retrospective studies, and economic models were included. These studies report incremental cost-effectiveness ratios ranging from cost savings of $13 975 per life-year saved (LYS) to an incremental cost of $114 917 per LYS for ICD therapy. Differences were due to study type, cost-reporting methodology, ICD technology used, and length of follow-up. Assuming current technology and physician practice patterns, we find that ICD total therapy costs may break even in 1 to 3 years.

CONCLUSIONS

Recent literature suggests that ICDs are a cost-effective therapy for management of life-threatening ventricular tachyarrhythmias. The advent of new technology and patient management practices should further improve the cost-effectiveness of ICD therapy. Future studies of ICD cost-effectiveness should address the implications of truncated follow-up periods and quality of life.

Are QALYs an appropriate measure for valuing morbidity in acute diseases?

In this paper, we examine the problems associated with using quality adjusted life years (QALYs) as the measure of effectiveness to evaluate interventions for acute conditions. We illustrate the way in which using commonly accepted benchmarks for costs per QALY, in order to adopt interventions for acute conditions, might result in decisions that are not consistent with maximizing net societal benefit. We suggest that an alternate methodology, such as willingness to pay, may be more appropriate to make allocation decisions for acute conditions.

Cost-effectiveness of stress-echocardiography

Because of constraints on the costs of providing medical care, cardiologists in the future will find themselves challenged to provide care for their patients in the most cost-effective manner possible. Although stress-echocardiography has been shown to compare favorably with other tests in diagnostic accuracy, data on cost-effectiveness are scarce. In this article, general concepts of cost-effectiveness as they relate to stress-echocardiography are reviewed and the available literature is summarized. Although definitive data are lacking, there is evidence to suggest that stress-echocardiography may prove to be cost-effective in several clinical situations.

Who needs an implantable defibrillator?

Ventricular arrhythmias account for 80% of sudden cardiac deaths. The implantable defibrillator (ICD) is an effective means of preventing these deaths. This article discusses which patients may benefit from ICD implantation and addresses the cost-effectiveness of their use.

Cardiac rehabilitation in the elderly

Rehabilitation for patients with heart disease consists of exercise training, behavioral interventions, counseling, and education with the goal of improving physiologic and psychosocial status. The Cardiac Rehabilitation Clinical Practice Guidelines, recently published in the United States, list the most substantial benefits of cardiac rehabilitation as an improvement in exercise tolerance, symptoms, blood lipid levels, and psychosocial well-being, and a reduction in cigarette smoking, stress, and mortality. With the evidence-base on the elderly in the Guidelines derived from 1 non-randomized controlled trial and 7 observational studies, the efficacy and effectiveness of cardiac rehabilitation is based almost exclusively on data generated on young and middle-aged males. We have located an additional 10 randomized and 2 non-randomized controlled trials published since the Guidelines, but only one provided age-specific data. The elderly are the fastest growing segment of the population, and may be more responsive to the effects of cardiac rehabilitation as they often have greater initial disability and less independence than younger patients. While referral of elderly persons to cardiac rehabilitation services appears safe and warranted in the secondary prevention of heart disease, the lack of rigorous scientific evidence has created an important clinical research and clinical policy vacuum which urgently needs to be filled.

A randomized, double-blind comparison of intravenous diltiazem and digoxin for atrial fibrillation after coronary artery bypass surgery

BACKGROUND

Atrial fibrillation (AF) after coronary bypass graft surgery may result in hypotension, heart failure symptoms, embolic complications, and prolongation in length of hospital stay (LOHS). The purpose of this study was to determine whether intravenous diltiazem is more effective than digoxin for ventricular rate control in AF after coronary artery bypass graft surgery. A secondary end point was to determine whether ventricular rate control with diltiazem reduces postoperative LOHS compared with digoxin.

METHODS AND RESULTS

Patients with AF and ventricular rate > 100 beats/min within 7 days after coronary artery bypass graft surgery were randomly assigned to receive intravenous therapy with diltiazem (n = 20) or digoxin (n = 20). Efficacy was measured with ambulatory electrocardiography (Holter monitoring). Safety was assessed by clinical monitoring and electrocardiographic recording. LOHS was measured from the day of surgery. Data were analyzed with the intention-to-treat principle in all randomly assigned patients. In addition, a separate intention-to-treat analysis was performed excluding patients who spontaneously converted to sinus rhythm. In the analysis of all randomly assigned patients, those who received diltiazem achieved ventricular rate control (> or = 20% decrease in pretreatment ventricular rate) in a mean of 10 +/- 20 (median 2) minutes compared with 352 +/- 312 (median 228) minutes for patients who received digoxin (p < 0.0001). At 2 hours, the proportion of patients who achieved rate control was significantly higher in patients treated with diltiazem (75% vs 35%, p = 0.03). Similarly, at 6 hours, the response rate associated with diltiazem was higher than that in the digoxin group (85% vs 45%, p = 0.02). However, response rates associated with diltiazem and digoxin at 12 and 24 hours were not significantly different. At 24 hours, conversion to sinus rhythm had occurred in 11 of 20 (55%) patients receiving diltiazem and 13 of 20 (65%) patients receiving digoxin (p = 0.75). Results of the analysis of only those patients who remained in AF were similar to those presented above. There was no difference between the diltiazem-treated and digoxin-treated groups in postoperative LOHS (8.6 +/- 2.2 vs 7.7 +/- 2.0 days, respectively, p = 0.43).

CONCLUSIONS

Ventricular rate control occurs more rapidly with intravenous diltiazem than digoxin in AF after coronary artery bypass graft surgery. However, 12- and 24-hour response rates and duration of postoperative hospital stay associated with the two drugs are similar.

Cardiac electrophysiology studies and ablation procedures: a literature review

This literature review is focused on issues related to the development and usefulness of cardiac electrophysiology studies and ablation procedures. During the past decade, the efficacy of these developments has been proven. The resultant emergence of specialists trained as electrophysiologists represents an important milestone in the advancement of cardiology departments internationally. The majority of research papers on the subject have been published within the past 5 years. Most of the research has evolved from North America and Britain. On searching the literature, it was found that many gaps remain. There is a striking dearth of documented data regarding electrophysiology studies and ablation therapy within the Irish medical and nursing literature, and no previous literature review on the topic was found in a wider search. This paper provides an overview of the strengths and weaknesses associated with these procedures.

Cost-effectiveness of screening for asymptomatic carotid atherosclerotic disease

BACKGROUND AND PURPOSE

The value of screening for asymptomatic carotid stenosis has become an important issue with the recently reported beneficial effect of endarterectomy. The purpose of this study is to evaluate the cost-effectiveness of using Doppler ultrasound as a screening tool to select subjects for arteriography and subsequent surgery.

METHODS

A computer model was developed to simulate the cost-effectiveness of screening a cohort of 1000 men during a 20-year period. The primary outcome measure was incremental present-value dollar expenditures for screening and treatment per incremental present-value quality-adjusted life-year (QALY) saved. Estimates of disease prevalence and arteriographic and surgical complication rates were obtained from the literature. Probabilities of stroke and death with surgical and medical treatment were obtained from published clinical trials. Doppler ultrasound sensitivity and specificity were obtained through review of local experience. Estimates of costs were obtained from local Medicare reimbursement data.

RESULTS

A one-time screening program of a population with a high prevalence (20%) of > or = 60% stenosis cost $35130 per incremental QALY gained. Decreased surgical benefit or increased annual discount rate was detrimental, resulting in lost QALYs. Annual screening cost $457773 per incremental QALY gained. In a low-prevalence (4%) population, one-time screening cost $52588 per QALY gained, while annual screening was detrimental.

CONCLUSIONS

The cost-effectiveness of a one-time screening program for an asymptomatic population with a high prevalence of carotid stenosis may be cost-effective. Annual screening is detrimental. The most sensitive variables in this simulation model were long-term stroke risk reduction after surgery and annual discount rate for accumulated costs and QALYs.

Cardiac pacing following surgery for acquired heart disease

BACKGROUND

This study is comprised of 3493 consecutive patients who underwent open heart surgery at our institution. Data on all patients were collected prospectively.

METHODS

In 45 patients (Group P) (1.3%), a permanent pacemaker (PP) was inserted postoperatively. For the purpose of the study, these patients were compared to 3448 patients (Group NP) who did not require insertion of a PP after surgery. Mean follow-up was 33 months (range 1.5 to 66).

RESULTS

We found Group P patients were older (64.8 +/- 11.0 vs 61.0 +/- 11.0 years, p < 0.05), had a higher proportion of elderly (> 70 years) 36% vs 19%, p = 0.01), and of female patients (48.8% vs 22.7%, p < 0.001) compared to Group NP. Group P also had a higher incidence of preoperative rhythm abnormalities (26.6% vs 5.7%, p < 0.0001), redo surgery (13.3% vs 4.6%, p = 0.02), aortic valve surgery (48.8% vs 10.8%, p < 0.001), and tricuspid valve surgery (repair 3, replacement 1) (8.8% vs 0.5%, p < 0.001), in addition to a higher proportion of patients in whom cold (vs warm) blood cardioplegia was used (68.8% vs 52.3%, p = 0.03). Indication for postoperative PP was sick sinus syndrome (SSS) in nine patients; atrial fibrillation in eight patients; atrioventricular block (AVB) in 27 patients; and combined AVB/SSS in 1 patient. There were no operative deaths in Group P. Necessity for PP after heart surgery had a significant impact on resource utilization resulting in prolonged ventilation (3.1 +/- 7.5 vs 1.4 +/- 3.3 days, p < 0.01), intensive care unit (5.1 +/- 10.2 vs 2.5 +/- 4.0 days, p < 0.01), and postoperative hospital stay (18.0 +/- 13.4 vs 8.1 +/- 9.4 days, p < 0.01).

CONCLUSIONS

By multivariate logistic regression (odds ratio and p value in parentheses), aortic valve surgery (8.23, p = 0.001), the absence of preoperative sinus rhythm (5.60, p = 0.001), postoperative myocardial infarction (3.46, p = 0.024), and female gender (2.52, p = 0.003), were found to be independent predictors for PP requirement post surgery.

Cardiac electrophysiology: a cost-effective approach

Clinical cardiac electrophysiology is a relatively new discipline, heavily dependent upon new technology that is often expensive. In cardiac pacing, no effective alternative to permanent pacing usually exists for patients with Class I indications, so cost-reduction strategies involve appropriate selection and utilization of hardware and facilities. Cost-effective utilization of radiofrequency ablation and implantable cardioverter-defibrillators requires that these techniques be compared with alternative therapies, usually antiarrhythmic drugs. Both ablation and defibrillator implantation can be shown to be cost effective in selected populations, but a cost-conscious approach to procedures and patient selection can make them cost effective in a broad range of patients.

Estimating the cost-effectiveness of stereotaxic biopsy for nonpalpable breast abnormalities: a decision analysis model

RATIONALE AND OBJECTIVES

We examined the clinical and economic trade-offs of shifting from surgical excisional biopsy to stereotaxic core breast biopsy for evaluating non-palpable, mammographically detected breast lesions.

METHODS

A decision analysis model compared strategies beginning with excisional or stereotaxic core biopsy for hypothetical cohorts of 1,000 women. All women with negative initial biopsies had a 6-month follow-up mammogram. Sensitivities and specificities were based on the literature and expert estimates. Pretest probabilities of invasive cancer and in situ cancer were each 10% based on mammographic features. Adjusted costs were based on an audit of patients evaluated at the Medical College of Virginia and physician relative value units.

RESULTS

Per 1,000 women, with an expected rate of 100 invasive and 100 in situ cancers, the stereotaxic core biopsy strategy would initially miss 6.7 invasive and 12.4 in situ cases. Most of these would be detected at 6-month follow-ups. Of the women having a stereotaxic core biopsy, 75.7% avoided a surgical procedure. Using stereotaxic core biopsy saved $804 per woman. Continuing to initially use surgical biopsy, total management costs were an additional $42,100 per each case of early detected invasive or in situ cancer. A speculative sensitivity analysis, in which the prognosis of invasive cancer was worse if diagnosis was delayed by 6 months, indicated that surgical biopsy had an incremental cost of $156,700 per additional life year gained.

CONCLUSION

Using conservative estimates for the false-negative rate of stereotaxic core breast biopsy, widespread use of stereotaxic biopsy is projected to have substantial cost savings with a slight compromise in the rate of early detection. Whether the decremental cost-effectiveness is acceptable is dependent on the natural history of cancers whose diagnosis is delayed.

Cost-effectiveness analysis in heart disease, Part II: Preventive therapies

Cost-effectiveness analysis of preventive therapies are reviewed in the following categories: lipid lowering, hypertension, smoking cessation, exercise, and anticoagulation. From review of 8 analyses, cost-effectiveness of primary prevention via cholesterol lowering drugs is generally expensive, whereas that of secondary prevention generally is favorable. However, targeting by age, coexisting risk factors, and gender strongly influence results that are also sensitive to drug costs. Treatment of hypertension (5 analyses) is cost-effective in virtually all patient populations and circumstances and for a wide variety of drugs. It is more so with coexisting risk. Issues relating to compliance and drug costs are important. Smoking cessation (4 analyses) is highly cost-effective and worthwhile. However, data on recidivism are incomplete, and cessation may be more difficult to achieve in the general population versus study patients. In one analysis, an exercise program was found to be cost-effective in prevention of coronary heart disease. Anticoagulants have been analyzed in various circumstances. Their cost-effectiveness is favorable for prosthetic valves, although sensitive to imprecision in monitoring. It is also favorable for mitral stenosis in the presence of atrial fibrillation but not normal sinus rhythm. Cost-effectiveness of heparinization for prosthetic valve patients undergoing surgery is rather variable and depends on type of surgery (major versus minor) and type of valve. Many topics in anticoagulant therapy remain to be explored from a cost-effectiveness point of view.