Cost effectiveness of cholesterol-lowering therapy in The Netherlands. Simvastatin versus cholestyramine

Systematic Review of Validity Assessments of Framingham Risk Score Results in Health Economic Modelling of Lipid-Modifying Therapies in Europe

BACKGROUND

The Framingham Risk Score is used both in the clinical setting and in health economic analyses to predict the risk for future coronary heart disease events. Based on an American population, the Framingham Risk Score has been criticised for potential overestimation of risk in European populations.

OBJECTIVE

We investigated whether the use of the Framingham Risk Score actually was validated in health economic studies that modelled the effects of lipid-lowering treatment with statins on coronary heart disease events in European populations.

METHODS

In this systematic literature review of all relevant published studies in English (literature searched September 2016 in PubMed, EMBASE and SCOPUS), 99 studies were identified and 22 were screened in full text, 18 of which were included. Key data were extracted and synthesised narratively.

RESULTS

The only type of validation identified was a comparison against coronary heart disease risk data from one primary preventive and one secondary preventive clinical investigation, and from observational population data in one study. Taken together, those three studies reported an overall satisfactory accuracy in the results obtained by Framingham Risk Score predictions, but the Framingham Risk Score tended to underestimate non-fatal myocardial infarctions. In five studies, potential issues in applying the Framingham Risk Score on a European population were not addressed.

CONCLUSION

Further studies are needed to ascertain that the Framingham Risk Score can accurately predict cardiovascular outcome in health economic modelling studies on lipid-lowering therapy in European populations. Future modelling studies using the Framingham Risk Score would benefit from validating the results against other data.

Cost-effectiveness of statins revisited: lessons learned about the value of innovation

BACKGROUND

The economic evaluation of statins has undergone a development from risk-factor-based models to modeling of hard end points in clinical trials with a shift back to risk-factor models after increased confidence in their predictive power has now been established. At this point, we can look back on the historical economic data on simvastatin to see what lesson regarding reimbursement we can learn.

METHODS

Historical data on the usage and sales of simvastatin in Sweden were combined with published epidemiological and clinical data to calculate the social value of simvastatin to the present day and to make projection until projected until 2018. The distribution of the social surplus was calculated by taking the costs born by society and the producer of the drug into consideration.

RESULTS

The cost of simvastatin fell drastically following patent expiration, although the number of treated patients has continued to grow. Presently, the use of simvastatin is close to cost neutrality taking direct and indirect cost savings from reduced morbidity into account. However, the major part of the social surplus generated comes from the value of improved quality-adjusted survival. Of the social surplus generated, the producer appropriated 20-43% of the value during the on-patent period, a figure dropping to 1% following loss of exclusivity. The total producer surplus between 1987 and 2018 is 2-5% of the total social surplus.

CONCLUSION

Only a small part of the surplus value generated was appropriated by the producer. A regulatory and reimbursement approach that favors early market access and coverage with evidence development as opposed to long-term trials as a pre-requisite for launch is more attractive from both a company and social perspective.

Economic evaluations of cholesterol-lowering drugs: a critical and systematic review

The wide availability of economic evaluations and their increasing importance for decision making emphasises the need for economic evaluations that are methodologically sound. The aim of this review was to provide users of economic evaluations of cholesterol-lowering drugs with an insight into the quality of these evaluations. By focusing on the most relevant studies, the gap between research and policy making may be narrowed. A systematic review was conducted. All Dutch and English publications on economic evaluations of cholesterol-lowering drugs were identified by searching PubMed, the Centre for Reviews and Dissemination database (CRD), the NHS Economic Evaluation Database (NHS EED), the Health Technology Assessment database (HTA) and the Database of Abstracts of Reviews of Effects (DARE). A search strategy was set up to identify the articles to be included. The quality of these articles was assessed using Drummond's checklists. The scoring was performed by at least two reviewers. When necessary, disagreement between these reviewers was decided upon in a consensus meeting. We calculated an average quality score for the included articles. The search identified 1390 articles, of which 23 were included. Most studies measured the costs per life-year gained. The overall score per study was disappointing and varied between 2.7 and 7.7, with an average of 5.5. Most studies scored high on the measurement of costs and consequences, whereas the establishment of effectiveness left room for improvement. Only two studies included a well performed incremental analysis. This study noted an increase of quality of economic evaluations over time, suggesting the value of cost-effectiveness studies for policy decisions increases over time. In general, piggy-back evaluations tended to score higher on quality and may therefore be more valuable in decision making.

Variability of cost-effectiveness estimates for pharmaceuticals in Western Europe: lessons for inferring generalizability

OBJECTIVES

It has long been suggested that, whereas the results of clinical studies of pharmaceuticals are generalizable from one jurisdiction to another, the results of economic evaluations are location dependent. There has been, however, little study of the causes of variation, whether differences in study results among countries are systematic, or whether they are important for decision making.

METHODS

A literature search was conducted to identify economic evaluations of pharmaceuticals conducted in two or more European countries. The studies identified were then classified by methodological type and analyzed to assess their level of variability and to identify the main causes of variation. Assessments were also made of the extent to which differences in study results among countries were systematic and whether they would lead to a different decision, assuming a range of values of the threshold willingness-to-pay for a life-year or quality-adjusted life-year (QALY).

RESULTS

In total 46 intercountry drug comparisons were identified, 29 in multicountry studies and 17 in comparable single country studies that were considered to be sufficiently similar in terms of methodology. The type of study (i.e., trial-based or modeling study) had some impact on variability, but the most important factor was the extent of variation across countries in effectiveness, resource use or unit costs, allowed by the researcher's chosen methodology. There were few systematic differences in study results among countries, so a decision maker in country B, on seeing a recent economic evaluation of a new drug in country A, would have little basis on which to predict whether the drug, if evaluated, would be more or less cost-effective in his or her country. Given the extent of variation in cost-effectiveness estimates among countries, the importance of this for decision making depends on decision makers' thresholds in willingness-to-pay for a QALY or life-year. If a cost-effectiveness threshold (i.e., willingness-to-pay) for a life-year or QALY of dollar 50,000 were assumed, the same conclusion regarding cost-effectiveness would be reached in most cases.

CONCLUSION

This review shows that cost-effectiveness results for pharmaceuticals vary from country to country in Western Europe and that these variations are not systematic. In addition, constraints imposed by analysts may reduce apparent variability in the estimates. The lessons for inferring generalizability are not straightforward, although the implications of variation for decision making depend critically on the cost-effectiveness thresholds applying in Western Europe.

Health-related quality of life with coronary heart disease prevention and treatment

Estimating the net benefits of dyslipidemia treatment is limited by the lack of comprehensive and standardized information on the preference for dyslipidemia and coronary heart disease. In a hospital-based study, we measured the health-related quality of life (HRQOL) of healthy participants without dyslipidemia (n = 307) and with dyslipidemia (n = 251) and patients with coronary heart disease (n = 320). Compared to the healthy participants without dyslipidemia, those with dyslipidemia reported lower adjusted mean scores on the Rating Scale (-2.8 points, P = 0.02) and the SF-36 General Health Scale (-3.3 points, P = 0.02). No differences were observed on the Time Trade-off and the Standard Gamble Scales. Coronary patients reported lower scores on all preference scales and most SF-36 scales. The causes of the small but real reduction in HRQOL reported by dyslipidemic individuals should be identified in order to optimize the net benefits of lipid therapy.

Cost-effectiveness of cholesterol-lowering therapies according to selected patient characteristics

BACKGROUND

The National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel II) recommends treatment guidelines based on cholesterol level and number of risk factors.

OBJECTIVE

To evaluate how the cost-effectiveness ratios of cholesterol-lowering therapies vary according to different risk factors.

DESIGN

Cost-effectiveness analysis.

DATA SOURCES

Published data.

TARGET POPULATION

Women and men 35 to 84 years of age with low-density lipoprotein cholesterol levels of 4.1 mmol/L or greater (> or =160 mg/dL), divided into 240 risk subgroups according to age, sex, and the presence or absence of four coronary heart disease risk factors (smoking status, blood pressure, low-density lipoprotein cholesterol level, and high-density lipoprotein cholesterol level).

TIME HORIZON

30 years.

PERSPECTIVE

Societal.

INTERVENTIONS

Step I diet, statin therapy, and no preventive treatment for primary and secondary prevention.

OUTCOME MEASURES

Incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

Incremental cost-effectiveness ratios for primary prevention with step I diet ranged from $1900 per quality-adjusted life-year (QALY) gained to $500000 per QALY depending on risk subgroup characteristics. Primary prevention with a statin compared with diet therapy was $54000 per QALY to $1400000 per QALY. Secondary prevention with a statin cost less than $50000 per QALY for all risk subgroups.

RESULTS OF SENSITIVITY ANALYSIS

The inclusion of niacin as a primary prevention option resulted in much less favorable incremental cost-effectiveness ratios for primary prevention with a statin (>$500000 per QALY).

CONCLUSIONS

Cost-effectiveness of treatment strategies varies significantly when adjusted for age, sex, and the presence or absence of additional risk factors. Primary prevention with a step I diet seems to be cost-effective for most risk subgroups but may not be cost-effective for otherwise healthy young women. Primary prevention with a statin may not be cost-effective for younger men and women with few risk factors, given the option of secondary prevention and of primary prevention in older age ranges. Secondary prevention with a statin seems to be cost-effective for all risk subgroups and is cost-saving in some high-risk subgroups.

A population-based treat-to-target pharmacoeconomic analysis of HMG-CoA reductase inhibitors in hypercholesterolemia

The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors have become the drugs of choice for the treatment of patients with hypercholesterolemia. However, one of the major concerns with these drugs is cost. In an attempt to develop a cost-effective treatment strategy for patients referred to our lipid clinic, we conducted a meta-analysis to estimate the lipid-lowering efficacy of the various HMG-CoA reductase inhibitors alone or in combination with niacin or cholestyramine. Based on cholesterol-lowering efficacy estimates derived from a literature-based meta-analysis, we performed a population-based treat-to-target analysis. Fifty-six trials with 101 monotherapy cohorts and 20 trials with 31 combination-therapy cohorts (573 patients) were included in the meta-analysis. Based on reduction in low-density lipoprotein cholesterol (LDL-C), the most effective monotherapy was atorvastatin and the least effective monotherapy was fluvastatin. Combination therapy was more effective in reducing LDL-C than monotherapy with the respective HMG-CoA reductase inhibitor. However, on the basis of dollars spent per percentage of LDL-C reduction, combination therapy was frequently less cost-effective than monotherapy. In addition, combination therapy was associated with a higher rate of noncompliance and a greater risk of drug-drug interactions. As a result, we based our treat-to-target analysis on the use of monotherapy as first-line treatment, with combination therapy reserved for patients failing to achieve the target LDL-C levels of the US National Cholesterol Education Program Adult Treatment Panel II (NCEP ATP-II) with monotherapy. In the population-based treat-to-target analysis, atorvastatin was the most cost-effective drug for high-risk patients (those with coronary heart disease [CHD]), whereas fluvastatin was the most cost-effective agent for low-risk patients (<2 risk factors for CHD) and moderate-risk patients (> or =2 risk factors for CHD). If 1 drug is chosen to treat all patients (i.e., in cases of formulary restriction), atorvastatin would be the most cost-effective agent. In adapting the findings on cholesterol-lowering efficacy from this analysis to our lipid clinic, we concluded that the most cost-effective treatment approach is to individualize the selection of an HMG-CoA reductase inhibitor based on both coronary risk and the LDL-C reduction required to achieve NCEP ATP-II goals. Based on our results, 2 agents--atorvastatin and fluvastatin--should be available on the formulary.

The economics of hypercholesterolemia and lipid-lowering therapy: a brief historical tour

The first formal economic evaluation of a lipid-lowering intervention was conducted almost 20 years ago. The field exploded in the mid-1980s following the publication of findings from the Lipid Research Clinics Coronary Primary Prevention Trial (LRC-CPPT), in which the bile-acid sequestrant, cholestyramine, was reported to reduce the incidence of coronary artery disease in adults with significant elevations in cholesterol. Almost all of the early pharmacoeconomic studies that followed focused on this agent. Later in the decade, the introduction of lovastatin, the first 3-hydroxy-3 methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (or "statin"), revolutionized the treatment of hypercholesterolemia, as it was significantly more effective than earlier agents (as were the other statins that followed it). Pharmacoeconomic studies of the statins generally have reported that, despite their higher cost, they are significantly more cost-effective than bile acid sequestrants. Recent long-term clinical trials, such as the West of Scotland Coronary Prevention Study (WOSCOPS) and the Scandinavian Simvastatin Survival Study (4S), have provided firm evidence of the benefits of the statins in both the primary and secondary prevention of coronary artery disease. Formal economic evaluations were incorporated into most of these end-point studies-in contrast to morbidity and mortality trials of earlier lipid-lowering agents-and results from these evaluations are just now becoming available. The availability of primary economic data derived directly from large-scale, long-term clinical trials raises important questions about the future role of modeling in this area.

Strategies for the management of hypercholesterolaemia: a systematic review of the cost-effectiveness literature

OBJECTIVE

To review research addressing the management of cholesterol in the prevention of coronary heart disease in order to assess the cost-effectiveness of such interventions.

METHODS

A systematic review of economic evaluations identified through searches of MEDLINE and the Social Sciences Citation Index revealed 38 studies addressing the cost-effectiveness of cholesterol management. They were distinguished according to screening approaches, dietary advice and drug treatment. Most studies were not associated directly with clinical trial results, but adopted economic modelling approaches.

RESULTS

Whilst there is general agreement among the majority of analyses, studies of cholesterol management concerned with screening strategies were extremely sensitive to changes in their assumptions; so much so that only a limited emphasis may be placed on specific cost-effectiveness ratios and the conclusions drawn from them. All studies considered direct costs, though many were limited to drug costs. The cost-effectiveness of primary prevention by cholesterol-lowering drugs is highly variable, depending on age at initiation of treatment and cardiovascular risk profile. Pharmacological intervention is least cost-effective in the young and the elderly. The cost-effectiveness of cholesterol-reducing agents improves when they are targeted at those at high risk. HMG-CoA reductase inhibitors are generally more effective and more cost-effective at reducing cholesterol-related coronary events than other medications.

CONCLUSION

The methods and economic data upon which these studies are based need to be improved if robust policy conclusions are to be formulated.

Incorporating future costs in medical cost-effectiveness analysis: implications for the cost-effectiveness of the treatment of hypertension

It has been shown that the difference between consumption and production during life years gained should be included as a cost in cost-effectiveness analysis. In this study the authors estimate the impact of including these future costs on the cost-effectiveness of the treatment of hypertension in Sweden. The cost per quality-adjusted life year (QALY) gained changes little among young men and women due to the addition of future costs, but increases by about $14,000 for middle-aged men and women and about $27,000 for older men and women. When future costs are not included, the cost per QALY gained is generally lowest among older men and women, but when future costs are included, the cost per QALY gained is generally lowest among middle-aged men and women. The authors conclude that the total resource consequences of changes in mortality should be routinely considered in cost-effectiveness analyses.

Economic evaluation in support of national health policy: the case of The Netherlands

This article focuses on economic evaluation as an instrument to support national health policy in the Netherlands. National health policy concerns decision-making on which technologies may enter the health care market, which health care services are included in the package of health care benefits and under what conditions, and what the geographical distribution of medical services and facilities should be. Regarding the latter two issues in particular, the actual and potential role of economic evaluation in health policy is discussed. From the Dutch experience we can learn that a close cooperation between researchers and policy-makers helps to enlarge the impact of economic appraisal on policy-making and that incorporation of the right (financial) incentives is vital to the use of economic appraisal in health care decision-making.

Economic implications of thrombolysis or operation as the initial treatment modality in acute peripheral arterial occlusion

BACKGROUND

Thrombolytic agents have been used to treat arterial occlusion for almost 40 years. Recently, an investigation of the costs associated with two treatment options for acute peripheral arterial occlusions, thrombolysis and surgical intervention, was completed. The availability of hospital cost data for patients enrolled in the thrombolytic and operative treatment groups provided a basis with which to accurately assess the financial impact of the different treatment strategies, both from a purely financial standpoint and in relation to outcome.

METHODS

The patient base was composed of 114 patients with acute limb ischemia of less than 7 days' duration. The patients were randomly assigned to receive urokinase (n = 57) or to undergo an operation (n = 57) as the initial therapeutic intervention. Patients in the thrombolytic group underwent standard intraarterial diagnostic arteriography, and patients with embolic events, in whom complete lysis of all embolic and propagated thrombotic material was achieved, were subsequently treated with heparin and long-term warfarin (Coumadin) therapy. The economic analysis was undertaken after the completion of the trial. Statistical comparisons between groups were made with the Student t test for continuous, normally distributed data. Mortality and limb salvage rates were calculated from Kaplan-Meier curves, appropriate for the censored nature of the data.

RESULTS

The total treatment costs did not differ significantly between the two treatment groups ($22,171 +/- $4,959 in the thrombolytic group and $19,775 +/- $5,253 in the operative group). The total hospital charges were similar between the two groups. Overall, the total charges were remarkably similar between the two treatment groups, averaging $40,823 +/- $8,764 in the thrombolytic group and $41,930 +/- $10,398 in the operative group.

CONCLUSIONS

An economic analysis of the data confirmed that the total economic impact of thrombolysis approximated that of initial operative therapy. The improved clinical outcome in patients treated with thrombolysis suggests that this modality may be appropriate as the initial therapeutic intervention in the select group of patients seen within the first few hours of an acute peripheral arterial occlusive event.

Cost-effectiveness of alternative interventions for the prevention and treatment of coronary heart disease

Although mortality from coronary heart disease (CHD) in Australia has fallen dramatically since the 1960s, it still remains the major cause of death in Australia and poses a significant burden on the economy. Even though a number of studies have concluded that prevention has been the main determinant of the declines in CHD, a disproportionate amount of health-care expenditure is devoted to treatment rather than prevention. This paper reviews the international literature on the economic appraisal (costs and benefits) of alternative interventions for the treatment and prevention of CHD with the view of assessing whether there is sufficient evidence to justify a reallocation of resources away from treatment to prevention. First, few studies on the economic evaluation of CHD prevention and treatment programs have been undertaken in Australia, with most being from the United States and Europe. Second, assumptions about the specification, measurement and valuation of costs, and the epidemiological evidence on program effectiveness have varied. Third, health promotion and prevention programs are not necessarily more cost-effective than drug or surgical treatments for CHD. Individual interventions must be judged on their own merits. There is a need for a systematic evaluation of interventions for CHD using primary Australian data to better inform decision making on resource-allocation priorities. Such an evaluation should incorporate economic evaluation techniques.

Comparative evaluation of the safety and efficacy of HMG-CoA reductase inhibitor monotherapy in the treatment of primary hypercholesterolemia

OBJECTIVE

To evaluate the comparative efficacy and safety of the 4 currently available hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, fluvastatin, lovastatin, pravastatin, and simvastatin, in the treatment of primary hypercholesterolemia.

DATA SOURCES

English-language clinical studies, abstracts, and review articles identified from MEDLINE searches and bibliographies of identified articles. Unpublished data were obtained from the Food and Drug Administration in accordance with the Freedom of Information Act.

STUDY SELECTION

Placebo-controlled and comparative studies of HMG-CoA reductase inhibitor monotherapy in the treatment of primary hypercholesterolemia.

DATA EXTRACTION

Pertinent studies were selected and the data were synthesized into a review format.

DATA SYNTHESIS

The chemistry, pharmacology, and pharmacokinetics of the 4 HMG-CoA reductase inhibitors are reviewed. Clinical trials evaluating the hypocholesterolemic efficacy of the HMG-CoA reductase inhibitors are examined, and results on the comparative efficacy and safety of these agents are summarized. On a milligram-per-milligram basis, simvastatin is twice as potent as lovastatin and pravastatin. The hypocholesterolemic effects of fluvastatin appear to be approximately 30% less than that of lovastatin. In posttransplant patients receiving cyclosporine, safety has been documented for low doses of lovastatin and simvastatin, but when a higher dosage of an HMG-CoA reductase inhibitor is warranted, pravastatin should be considered the drug of choice because of a lower incidence of myopathy. Relevant data on the incidence of adverse effects are presented. Pertinent outcomes data from clinical trials evaluating the effect of HMG-CoA reductase inhibitors on atherosclerosis regression and coronary mortality, as well as published economic analyses of cholesterol-lowering agents, are summarized. Recommendations on the selection of an HMG-CoA reductase inhibitor in various clinical situations are provided.

CONCLUSIONS

The literature supports the comparable safety and tolerability of all 4 currently available HMG-CoA reductase inhibitors. Therefore, the choice of an HMG-CoA reductase inhibitor should depend on the extent of cholesterol lowering needed to meet the recommended treatment goal established by the National Cholesterol Education Program. Direct comparative studies are needed to confirm the relative, long-term cost-effectiveness of the various HMG-CoA reductase inhibitors in the treatment of primary hypercholesterolemia.

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.

Using cost-effectiveness analysis for formulary decision making: from theory into practice

The growth of expenditures on healthcare and pharmaceutical products is a concern to third-party payers because of the absence of market discipline (price signals that consumers face). Cost-effectiveness analysis is a method that allows third-party payers to systematically make judgements about the 'value for money' of these products. It moves beyond simple unit price comparisons of alternate interventions/products to consider the full stream of relevant cost and benefits. As formulary committees begin to adopt the systematic use of cost-effectiveness analyses to inform the debate, the exercise will move from an academic to a more practical application. This transition will require several important changes including defining the purpose of cost-effectiveness analysis, measurement of outcomes and data, format of reports, and contractual arrangements between the pharmaceutical industry and analysts. As more 'real world' experience is gained in the practical application of cost-effectiveness analysis, the quality of data will improve as will its value as an aid to decision making.

The cost-effectiveness of treating hypertension in elderly people--an analysis of the Swedish Trial in Old Patients with Hypertension (STOP Hypertension)

OBJECTIVES

The aim of this study was to estimate the cost-effectiveness of antihypertensive treatment in elderly people based on the results of the Swedish Trial in Old Patients with Hypertension (STOP Hypertension).

DESIGN

The STOP Hypertension study was a randomized trial comparing active antihypertensive treatment with a placebo. The risk of stroke, cardiovascular disease and total mortality was significantly reduced in the actively treated group compared to placebo.

SETTING

One hundred and sixteen primary health care centres in Sweden.

SUBJECTS

A total of 1627 hypertensive patients aged 70-84. No patient was lost to follow-up.

INTERVENTIONS

Antihypertensive treatment with beta blockers and diuretics for a mean follow-up of 25 months.

MAIN OUTCOME MEASURE

The cost-effectiveness ratio estimated as the net cost (the treatment cost minus saved costs of reduced cardiovascular morbidity) divided by the number of life-years gained (the increase in life expectancy from treatment).

RESULTS

The cost per life-year gained was estimated as SEK 5000 for men and SEK 15,000 for women ($1 = SEK 6; 1 pound = SEK 10). The cost per life-year gained did not exceed SEK 100,000 in any of the sensitivity analyses.

CONCLUSIONS

It is concluded that treatment of elderly hypertensive patients with beta blockers and/or diuretics is cost-effective according to the results of the STOP Hypertension study.

Treating hypercholesterolaemia with HMG CoA reductase inhibitors: a direct comparison of simvastatin and pravastatin

BACKGROUND

Simvastatin and pravastatin are both competitive inhibitors of the rate limiting enzyme for cholesterol biosynthesis (HMG CoA) reductase, but data from individual clinical trials suggest significant differences in potency for cholesterol reduction between the two drugs.

AIM

To assess any differences in efficacy and safety between simvastatin and pravastatin in a direct, comparative study.

METHODS

A double-blind, double-dummy, randomised study design was used, involving 48 patients with primary hypercholesterolaemia. Following a 6 week placebo baseline period, patients were randomly allocated to treatment with either simvastatin or pravastatin, commencing at a dose of 10 mg daily. The dose levels were titrated up to the recommended maximum effective dose of 40 mg daily at 6 weekly intervals if LDL cholesterol levels remained > or = 3.4 mmol/L. After 18 weeks of therapy, all patients were transferred to simvastatin therapy for a further 6 weeks, continuing at their week 18 dose level. Patients complied with a standard lipid lowering diet (containing < 30% of energy as total fat) throughout the study period.

RESULTS

Over the 18 week direct comparison of the two drugs, there was a significant difference (p < 0.001) in response between simvastatin and pravastatin for reduction in levels of total cholesterol (32% vs 21% respectively), LDL cholesterol (38% vs 27%) and apolipoprotein B levels (34% vs 23%). No significant difference in drug effect was seen for the small reduction in levels of apolipoprotein AI (5% vs 6% respectively), nor for the increased levels of apolipoprotein AII (14% vs 11%) and HDL cholesterol (11% vs 7%). Lp(a) levels remained unchanged. When pravastatin was replaced with simvastatin for the final 6 weeks of the study in the 23 patients initially randomised to pravastatin, there were further reductions (p < 0.01) in total and LDL cholesterol, and apolipoprotein B. These results establish the advantage of simvastatin over pravastatin in terms of efficacy, for the treatment of primary hypercholesterolaemia.

Selection of end points in economic evaluations of coronary-heart-disease interventions

Economic evaluations of interventions to lower blood pressure or cholesterol have used different outcome measures, or end points, in the denominator. Some have related the costs of interventions to improvements in physiologic end points such as mm Hg reduction in blood pressure. Some have related costs to avoidance of coronary heart disease (CHD) events or gains in life expectancy. Others have measured improvements in outcome in quality-adjusted life years (QALYs) gained. The different end points imply different analytic perspectives and different data requirements. The more ambitious analyses, though potentially more relevant in certain situations, require more controversial assumptions to be made. This paper illustrates the trade-offs of relevance, accuracy, and precision by reference to an evaluation of drug therapy for hypercholesterolemia undertaken in the United Kingdom. Estimates are given of cost per percentage cholesterol reduction, cost per CHD event avoided, cost per CHD-free year gained, cost per life year gained, and cost per quality-adjusted life year gained. In each case the assumptions required and the potential relevance of the estimate are discussed. The main findings are that: 1) some end points cannot be discounted to present values in a meaningful way and hence the timing of costs and outcomes cannot be reflected in the analysis; 2) the incorporation of quality-of-life adjustments for years on drug therapy and years post-CHD events greatly changes the cost-effectiveness ratios; 3) the rate of discount changes the pretreatment level of cholesterol for which cost per life year gained is equivalent to cost per quality-adjusted life year gained.(ABSTRACT TRUNCATED AT 250 WORDS)

Economic evaluation alongside cancer trials: methodological and practical aspects

A recent extension of clinical evaluation is "economic evaluation", which seeks to characterise each relevant alternative health care strategy in terms of a summary measure incorporating the costs and benefits of such strategies. In an economic evaluation, separate measurements of resource volumina and resource prices on the cost side, and separate measurements of survival and quality of life effects and valuation of these outcome effects on the benefit side are required. From these effect parameters, which should be calculated for all competing strategies considered in the analysis, the relative cost-effectiveness of one strategy as against the other can be derived. The degree of generalisability of the study results determines the validity of economic evaluation in decision-making. This depends on the generalisability of the clinical findings, and in this respect the so-called "piggyback" economic evaluation, which is added to a clinical trial, has its limitations. In the field of cancer, specific attention should be given to costs and effects occurring after non-mortality endpoints, to patient and family costs and to variations in treatments between settings of care. It is argued that conventional clinical trials and economic evaluations will integrate further in the future.

High cost technology in health care: a benefit or a burden?

The influence of high cost technology goes beyond its consequences for the selected patient groups that benefit from its application. Past and future technological developments have a variety of social, economic and ethical implications which have to be taken into account when balancing its costs and benefits to society. Departing from an economic perspective we describe a number of mechanisms underlying the emergence of high cost technology which help us to understand some of the characteristics of high cost technology, such as its focus on quality enhancement rather than on economy. To assess the actual performance of high cost technology in terms of efficiency and equity is difficult as there may be debate about the perspective guiding such assessment and as there still is scarce information on high cost technology in terms of these economic indicators. The increasing technological opportunities have triggered a wider debate on the desired evolution of our health care systems. In some countries there is a tendency to diminish government involvement in health care and emphasize private (for profit) enterprise as a reaction to not being able to finance all new high cost technology. The risks of such strategies are discussed briefly. We conclude that the main actors in health care should adjust their behaviour in order to accomplish the introduction of more cost-effective technologies and to achieve a more socially efficient distribution of their benefits.

Economic evaluation of lipid lowering--a feasibility test of the contingent valuation approach

A large number of cost-effectiveness analyses of treatment of high cholesterol levels have been published the last few years. Due to the inherent problems of cost-effectiveness analysis of prevention and the specific problems in the case of lipid lowering, it is important to test alternative approaches. This study reports the results of a pilot study of three benefit measures based on individual preferences. Willingness to pay (WTP), willingness to give up leisure time (WTGT) and maximum acceptable risk (MAR) for lowering cholesterol levels to normal were investigated among persons with hypercholesterolaemia in a postal survey. The respondents were on average prepared to pay about SEK 450 per month, to give up about 7 hours of leisure time per week or to take an immediate mortality risk of about 1.4% to get normal lipid levels. The WTP and WTGT questions seemed to be about equally acceptable, whereas the MAR question performed less well with respect to acceptability. It is concluded that especially WTP deserves further attention, due to its inherent advantages, since it performed at least as well as the other measures.

Cholesterol-lowering effects of a 10 mg daily dose of lovastatin in patients with initial total cholesterol levels 200 to 240 mg/dl (5.18 to 6.21 mmol/liter)

Subjects with plasma cholesterol levels greater than 240 mg/dl (6.21 mmol/liter) and those with greater than 200 mg/dl (5.18 mmol/liter) who have coronary artery disease, or those with 2 risk factors for ischemic heart disease who do not respond to a hypocholesterolemic diet should all be treated. Lovastatin, which is an inhibitor of hydroxymethygluteryl coenzyme A reductase, is a new agent for treating hypercholesterolemia and is administered in a dose of 20 to 80 mg/day. A study was conducted in which only 10 mg of lovastatin was given to 28 subjects with plasma cholesterol of 200 to 240 mg/dl (5.18 to 6.21 mmol/liter). Cholesterol plasma levels decreased in 19% and low-density lipoprotein cholesterol decreased by 24% from baseline levels after 20 weeks of treatment. All 28 patients decreased their cholesterol values to less than 200 mg% (5.18 mmol/liter), and only 1 had a low-density lipoprotein level greater than 130 mg% (3.36 mmol/liter) at termination of the study. Achievement of desirable values of cholesterol with 10 mg of lovastatin was accompanied by less adverse effects and with significant financial saving. The calculated saving for lovastatin consumers in the USA could be an amount of $60,000,000. Thus, it is recommended that this drug be manufactured in 10 mg tablets.

A computer simulation model for cost-effectiveness analysis of cardiovascular disease prevention

In this paper a computer simulation model for cost-effectiveness analysis of cardiovascular disease prevention is presented. Cost-effectiveness analysis makes it possible to compare the cost-effectiveness of different interventions in order to maximize the health effects for a given amount of resources. The computer simulation model was written in Turbo-Pascal to be used on an IBM-PC-compatible. The model was based on the 8-year logistic multivariate risk equations for CHD and stroke from the Framingham Heart Study, but the regression coefficients can easily be changed if local data exist. The main advantages with the model are that it is easy to use, transparent, and flexible. The model was mainly developed for scientific purposes, but should be useful also for educational purposes and clinical decision analysis. The modelling approach used should also be useful in many other medical areas.

Clinical benefits and cost-effectiveness of lowering serum cholesterol levels: the case of simvastatin and cholestyramine in The Netherlands

To assess the cost-effectiveness of cholesterol-reducing therapy with cholestyramine and simvastatin in the primary prevention of coronary artery disease in The Netherlands, a model of coronary artery disease incidence was used based on multivariate logistic risk functions from the Framingham study. For men with initial cholesterol levels of 8 mmol/liter, the cost per year of life saved of cholestyramine, expressed in Dutch guilders (NLG; 1 NLG = $0.50), ranges from approximately NLG 208,000 to NLG 483,000, depending on the patient's age at initiation of therapy. For simvastatin, cost-effectiveness ranges from NLG 46,000 to NLG 98,000 per year of life saved among this group of men. Similar differences between simvastatin and cholestyramine therapy prevail among women, although the costs per year of life saved for both agents are considerably higher. These results suggest that (1) simvastatin is substantially more cost effective than is cholestyramine; (2) simvastatin therapy compares favorably with other generally accepted medical practices, especially if treatment is initiated at an early age; and (3) as its long-term safety record becomes more established, simvastatin may become accepted as a drug of first choice in the treatment of persons with elevated serum cholesterol levels.