Cost-effectiveness of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors in the secondary prevention of cardiovascular disease: forecasting the incremental benefits of preventing coronary and cerebrovascular events

Evaluation of the cost-effectiveness of evolocumab in the FOURIER study: a Canadian analysis

BACKGROUND

Evolocumab, a proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor, has been shown to reduce low-density lipoprotein levels by up to 60%. Despite the absence of a reduction in overall or cardiovascular mortality in the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial, some believe that, with longer treatment, such a benefit might eventually be realized. Our aim was to estimate the potential mortality benefit over a patient's lifetime and the cost per year of life saved (YOLS) for an average Canadian with established coronary artery disease. We also sought to estimate the price threshold at which evolocumab might be considered cost-effective for secondary prevention in Canada.

METHODS

We calibrated the Cardio-metabolic Model, a well-validated tool for predicting cardiovascular events and life expectancy, to the reduction in nonfatal events seen in the FOURIER trial. Assuming that long-term treatment will eventually result in mortality benefits, we estimated YOLSs and cost per YOLS with evolocumab treatment plus a statin compared to a statin alone. We then estimated the annual drug costs that would provide a 50% chance of being cost-effective at willingness-to-pay values of $50 000 and $100 000.

RESULTS

In secondary prevention in patients similar to those in the FOURIER study, evolocumab treatment would save an average of 0.34 (95% confidence interval [CI] 0.27-0.41) life-years at a cost of $101 899 (95% CI $97 325-$106 473), yielding a cost per YOLS of $299 482. We estimate that to have a 50% probability of achieving a cost per YOLS below $50 000 and $100 000 would require annual drug costs below $1200 and $2300, respectively.

INTERPRETATION

At current pricing, the use of evolocumab for secondary prevention is unlikely to be cost-effective in Canada.

Years of life lost and healthy life-years lost from diabetes and cardiovascular disease in overweight and obese people: a modelling study

BACKGROUND

Despite the increased risk of cardiovascular disease and type 2 diabetes associated with excess bodyweight, development of a clinically meaningful metric for health professionals remains a challenge. We estimated the years of life lost and the life-years lost from diabetes and cardiovascular disease associated with excess bodyweight.

METHODS

We developed a disease-simulation model to estimate the annual risk of diabetes, cardiovascular disease, and mortality for people with BMI of 25-<30 kg/m(2) (overweight), 30-<35 kg/m(2) (obese), or 35 kg/m(2) and higher (very obese), compared with an ideal BMI of 18·5-<25 kg/m(2). We used data from 3992 non-Hispanic white participants in the National Nutrition and Examination Survey (2003-10) for whom complete risk factor data and fasting glucose concentrations were available. After validation of the model projections, we estimated the years of life lost and healthy life-years lost associated with each bodyweight category.

FINDINGS

Excess bodyweight was positively associated with risk factors for cardiovascular disease and type 2 diabetes. The effect of excess weight on years of life lost was greatest for young individuals and decreased with increasing age. The years of life lost for obese men ranged from 0·8 years (95% CI 0·2-1·4) in those aged 60-79 years to 5·9 years (4·4-7·4) in those aged 20-39 years, and years lost for very obese men ranged from 0·9 (0-1·8) years in those aged 60-79 years to 8·4 (7·0-9·8) years in those aged 20-39 years, but losses were smaller and sometimes negligible for men who were only overweight. Similar results were noted for women (eg, 6·1 years [4·6-7·6] lost for very obese women aged 20-39 years; 0·9 years [0·1-1·7] lost for very obese women aged 60-79 years). Healthy life-years lost were two to four times higher than total years of life lost for all age groups and bodyweight categories.

INTERPRETATION

Our estimations for both healthy life-years and total years of life lost show the effect of excess bodyweight on cardiovascular disease and diabetes, and might provide a useful health measure for discussions between health professionals and their patients.

FUNDING

Canadian Institutes of Health Research.

Projected cost-effectiveness of ezetimibe/simvastatin compared with doubling the statin dose in the United Kingdom: findings from the INFORCE study

OBJECTIVE

To evaluate the incremental cost-effectiveness ratio (ICER) of switching to ezetimibe/simvastatin (Eze/Simva) compared with doubling the submaximal statin doses, in patients with acute coronary syndrome (ACS) events in the INFORCE study.

METHODS

Lifetime treatment costs and benefits were computed using a Markov model. Model inputs included each patient's cardiovascular risk factor profile and actual lipid values at baseline and 12 weeks (endpoint). Cardiovascular event and drug costs were discounted at 3.5%. Age-specific utilities were based on UK literature values and non-coronary heart disease mortality rates on the Office of National Statistics data. In the INFORCE study, 384 patients taking statins at stable doses for ≥6 weeks before hospital admission were stratified by statin dose/potency (low, medium, and high) and then randomized to doubling the statin dose or switching to Eze/Simva 10/40mg for 12 weeks.

RESULTS

The Eze/Simva group (n=195) had a higher mean baseline total cholesterol than the double-statin group (n=189). Analyses were adjusted for baseline characteristics. In the INFORCE study, Eze/Simva reduced low-density lipoprotein cholesterol (LDL-C) by ∼30% (vs. 4% with doubling statin doses) and significantly enhanced LDL-C goal attainment. In the cost-effectiveness analysis, Eze/Simva conferred 0.218 incremental discounted quality-adjusted life year (QALY) at a discounted incremental cost of £2524, for an ICER of £11,571/QALY (95% confidence interval=£8181-£18,600/QALY). The ICER was £13,552/QALY, £11,930/QALY, and £10,148/QALY in the low-, medium-, and high-potency strata, respectively.

CONCLUSIONS

Switching to Eze/Simva 10/40 mg is projected to be a cost-effective treatment (vs. double-statin) in UK patients with ACS.

Empirically evaluating decision-analytic models

OBJECTIVES

Model-based cost-effectiveness analyses support decision-making. To augment model credibility, evaluation via comparison to independent, empirical studies is recommended.

METHODS

We developed a structured reporting format for model evaluation and conducted a structured literature review to characterize current model evaluation recommendations and practices. As an illustration, we applied the reporting format to evaluate a microsimulation of human papillomavirus and cervical cancer. The model's outputs and uncertainty ranges were compared with multiple outcomes from a study of long-term progression from high-grade precancer (cervical intraepithelial neoplasia [CIN]) to cancer. Outcomes included 5 to 30-year cumulative cancer risk among women with and without appropriate CIN treatment. Consistency was measured by model ranges overlapping study confidence intervals.

RESULTS

The structured reporting format included: matching baseline characteristics and follow-up, reporting model and study uncertainty, and stating metrics of consistency for model and study results. Structured searches yielded 2963 articles with 67 meeting inclusion criteria and found variation in how current model evaluations are reported. Evaluation of the cervical cancer microsimulation, reported using the proposed format, showed a modeled cumulative risk of invasive cancer for inadequately treated women of 39.6% (30.9-49.7) at 30 years, compared with the study: 37.5% (28.4-48.3). For appropriately treated women, modeled risks were 1.0% (0.7-1.3) at 30 years, study: 1.5% (0.4-3.3).

CONCLUSIONS

To support external and projective validity, cost-effectiveness models should be iteratively evaluated as new studies become available, with reporting standardized to facilitate assessment. Such evaluations are particularly relevant for models used to conduct comparative effectiveness analyses.

Economic evaluation of high-dose (80 mg/day) atorvastatin treatment compared with standard-dose (20 mg/day to 40 mg/day) simvastatin treatment in Canada based on the Incremental Decrease in End-Points Through Aggressive Lipid-Lowering (IDEAL) trial

BACKGROUND

The Incremental Decrease in End-Points Through Aggressive Lipid-Lowering (IDEAL) trial demonstrated incremental cardiovascular benefit of treatment with high-dose atorvastatin (80 mg/ day) versus standard-dose simvastatin (20 mg/day to 40 mg/day) in 8888 patients with a previous myocardial infarction (MI) over a median follow-up period of 4.8 years.

OBJECTIVES

To assess the cost-effectiveness of high-dose atorvastatin versus standard-dose simvastatin treatment in patients with a history of MI from a Canadian societal perspective.

METHODS

In a within-trial analysis, end point-related events, resources used and productivity losses occurring during the IDEAL trial were aggregated by treatment arm on an intention-to-treat basis to calculate the incremental cost per event avoided. Additionally, quality-adjusted survival was projected using a lifetime Markov model. Transition probabilities, workdays lost, use of study medication and cardiovascular hospitalization rates were based on IDEAL trial data. Hospitalization, study medication and productivity costs were included. Probabilistic and deterministic sensitivity analyses were performed.

RESULTS

Compared with standard-dose simvastatin, atorvastatin 80 mg led to 0.099 fewer events per patient and cost savings over 4.8 years of treatment. Over a lifetime horizon, atorvastatin 80 mg led to 0.023 qualityadjusted life years (QALYs) gained per patient at an incremental cost of $26,795/QALY gained. The incremental cost-effectiveness ratio remained below $50,000/QALY in 78% of 1000 simulations. Exclusion of indirect costs resulted in an incremental cost-effectiveness ratio of $38,834/QALY. Results were relatively sensitive to baseline age, but robust with respect to sex, baseline low-density lipoprotein cholesterol levels, diabetes status and hospitalization costs.

CONCLUSION

From a Canadian societal perspective, high-dose atorvastatin is cost-effective compared with standard-dose simvastatin in patients with a previous MI.

The clinical and economic burden of nonadherence with antihypertensive and lipid-lowering therapy in hypertensive patients

OBJECTIVE

We sought to determine lifetime costs, morbidity, and mortality associated with varying adherence to antihypertensive and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statin) therapy in a hypertensive population.

METHODS

A model was constructed to compare costs and outcomes under three adherence scenarios: no treatment, ideal adherence, and real-world adherence. Simulated patients' characteristics matched those of participants in the Anglo-Scandinavian Cardiac Outcomes Trial-Lipid-Lowering Arm and event probabilities were calculated with Framingham Heart Study risk equations. The real-world adherence scenario employed adherence data from an observational study of a US population; risk reductions at each level of adherence were based on linear extrapolations from clinical trials. Outputs included life expectancy, frequencies of primary and secondary coronary heart disease and stroke, and direct medical costs in 2006 US$. The incremental cost per life-year gained and incremental cost per event avoided were calculated comparing the three adherence scenarios.

RESULTS

Mean life expectancy was 14.73 years (no-treatment scenario), 15.07 (real-world adherence), and 15.49 (ideal adherence). The average number of cardiovascular events per patients was 0.738 (no treatment), 0.610 (real-world adherence), and 0.441 (ideal adherence). The incremental cost of real-world adherence versus no treatment is $30,585 per life-year gained, and ideal adherence versus real-world adherence is $22,121 per life-year gained.

CONCLUSIONS

Hypertensive patients taking antihypertensive and statin therapy at real-world adherence levels can be expected to receive approximately 50% of the potential benefit seen in clinical trials. Depending on its cost, the incremental benefits of an effective adherence intervention program could make it an attractive value.

Costs of stroke using patient-level data: a critical review of the literature

BACKGROUND AND PURPOSE

With decision-analytic models becoming more popular to assess the cost-effectiveness of health care interventions, the need for robust estimates on the costs of cerebrovascular disease is paramount. This study reports the results from a literature review of the costs of cerebrovascular diseases, and assesses the quality of the published evidence against a set of defined criteria.

METHODS

A broad literature search was conducted. Those studies reporting mean/median costs of cerebrovascular diseases derived from patient-level data in a developed country setting were included. Data were abstracted using standardized reporting forms and assessed against 4 predefined criteria: use of adequate methodologies, use of a population-based study, inclusion of premorbid resource use, and reporting of costs by different patient subgroups.

RESULTS

A total of 120 cost studies were identified. The cost estimates of stroke were compared by taking into account the effects of inflation and price differentials between countries. Average costs of stroke ranged from $468 to $146 149. Differences in costs were also found within country, with estimates in the USA varying 20-fold. Although the costing methodologies used were generally appropriate, only 5 studies were based on population-based studies, which are the gold standard study design when comparing incidence, outcome, and costs.

CONCLUSIONS

This review showed large variations in the costs of stroke, mainly attributable to differences in the populations studied, methods, and cost categories included. The wide range of cost estimates could lead to selection bias in secondary health economic analyses, with authors including those costs that are more likely to produce the desired results.

Preventing cardiovascular disease among Canadians: is the treatment of hypertension or dyslipidemia cost-effective?

BACKGROUND AND OBJECTIVES

The direct health care costs associated with treating hypertension and dyslipidemia continue to grow in most western countries, including Canada. Despite the proven effectiveness of hypertension and lipid therapies to prevent cardiovascular disease, the cost-effectiveness of long-term primary prevention, as currently advocated by Canadian treatment guidelines, remains to be determined.

METHODS

Therapeutic efficiency, defined as person-years of treatment per year of life saved (YOLS) and the cost-effectiveness of treatment were estimated for groups of Canadian adults, 40 to 74 years of age. The clinical indications for treatment were based on the Canadian national guidelines in 2005. Analyses focused on those without cardiovascular disease or diabetes using risk factor data from the Canadian heart health surveys and drug data from a national study, the MyHealthCheckUp survey. The expected impact of therapy was based on published results: statins would result in a 40% drop in low-density lipoprotein cholesterol and a 6% increase in high-density lipoprotein cholesterol, while hypertension therapy would result in a 6.4% drop in systolic and a 5.6% drop in diastolic blood pressure.

RESULTS

The estimated daily cost of statins was $1.98 versus $1.72 for antihypertensives. Overall, 2.33 million patients would be treated with lipid therapy and 2.34 million with antihypertensives. The average cost-effectiveness of lipid therapy would be approximately $16,700 per YOLS while hypertension therapy would be approximately $37,100 per YOLS. Lifelong lipid and hypertension therapy would be associated with 1.1 million and 472,000 life years saved at a national cost of $18.3 billion and $17.5 billion, respectively. However, hypertension treatment for some groups of Canadians appeared relatively expensive (more than $50,000 per YOLS) including men or women younger than 50 years of age. Despite attractive cost-effectiveness ratios, treatment appeared relatively inefficient (person-years of treatment per YOLS more than 100 years) for statin therapy among women younger than 50 years of age, and hypertension treatment for women younger than 60 years of age and men younger than 50 years of age.

CONCLUSIONS

Given Canadian guidelines, the treatment of dyslipidemia or hypertension in primary prevention appears economically attractive overall. However, for some groups of individuals, the forecasted future benefits appear to be relatively small given the many years of treatment that are required.

Determining the cost-effectiveness of preventing cardiovascular disease: are estimates calculated over the duration of a clinical trial adequate?

BACKGROUND

Economic analyses of randomized clinical trials often focus only on the results that are observed during the study. However, for many preventive interventions, associated costs and benefits will accrue over a patient's remaining lifetime. To determine the importance of the chosen time horizon, the cost-effectiveness (C/E) of ramipril therapy was calculated and compared in the Heart Outcomes Prevention Evaluation (HOPE), the Microalbuminuria, Cardiovascular, and Renal Outcomes in HOPE (MICRO-HOPE) and the Acute Infarction Ramipril Efficacy (AIRE) study versus the entire life expectancy (L/E) of potential patients.

METHODS

The Cardiovascular Disease Life Expectancy model, a validated Markov model, was calibrated to accurately forecast the results of each trial. These results were then extrapolated over the remaining L/E of hypothetical patients 55 to 75 years of age. The predicted change in L/E and associated direct health care costs for Canadians were calculated and discounted 3% annually.

RESULTS

In HOPE, the forecasted increased L/E averaged 0.06 years during the five-year study versus 1.3 years over the remaining years of L/E. The associated C/E of ramipril was $15,000 per year of life saved (YOLS) over the study duration and $8,500/YOLS over the remaining lifetime. For hypothetical patients, the C/E of ramipril over 4.5 years ranged from $6,700/YOLS to more than $58,300/YOLS and was lowest among elderly men. When the remaining L/E was considered, the C/E of ramipril was similar for men and women of all ages, ranging from $8,100/YOLS to $10,200/YOLS. The analyses of MICRO-HOPE and AIRE provided similar results.

CONCLUSION

The estimated efficacy and associated C/E of ramipril in HOPE, MICRO-HOPE and the AIRE study is extremely sensitive to the selected time horizon. Economic analyses beyond the duration of randomized clinical trials are required to fully evaluate the potential costs and benefits of long-term preventive therapies.

Estimating the cost effectiveness of ramipril used for specific clinical indications: comparing the outcomes in four clinical trials with a common economic model

BACKGROUND AND OBJECTIVES

Economic analyses of drug therapies are highly dependent on the clinical indications for treatment. The cost effectiveness of ramipril has been evaluated in numerous studies, usually based on the results of one specific clinical trial. We estimated the cost effectiveness of this drug across a range of currently accepted therapeutic indications, using a single health economic model and adjusted for quality of life, to compare the different outcomes observed in four clinical trials.

METHODS

The cardiovascular life expectancy model, a validated Markov model, was calibrated to accurately forecast the results of four trials including AIRE, HOPE, Micro-HOPE, and REIN. We then extrapolated these results over the remaining life expectancy of the patients enrolled in each study and adjusted for the quality of life associated with the observed outcomes. The cost per quality-adjusted life-year (QALY) was then calculated from the perspective of the Canadian healthcare system incorporating the estimated direct healthcare costs associated with treatments and outcomes.

RESULTS

After discounting all costs and outcomes 3% annually, the benefits associated with ramipril ranged from 0.74 QALYs in the AIRE study to 1.22 QALYs in Micro-HOPE. Treatment was estimated to be cost-saving for some patient groups, such as those in REIN. The highest cost-effectiveness ratio was observed among individuals enrolled in HOPE ($Can20 000 per QALY in 2002).

CONCLUSION

Treatment with ramipril appears to be economically attractive across a wide range of patient groups, including those with increased coronary risk and/or diabetes mellitus (HOPE and Micro-HOPE), those with congestive heart failure (AIRE), and those with non-diabetic nephropathy (REIN).

Controversies in the Treatment of Hypercholesterolemia in the Elderly: Who Should Be Treated and How?

High levels of low-density lipoprotein cholesterol may contribute to the development of coronary heart disease in the absence of other risk factors. This paper reviews major cholesterol prevention trials since 1994 concerning possible beneficial results of lowering cholesterol in persons over 65 years of age.

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.

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.

Effectiveness calculation in economic analysis: the case of statins for cardiovascular disease prevention

OBJECTIVES

This report aimed to evaluate the calculation of estimates of effectiveness in cost effectiveness analyses of statins for cardiovascular disease prevention.

METHODS

Methodological aspects were reviewed of seven primary studies (based on trial results) and 12 secondary modelling studies (extrapolated) on the cost effectiveness of statin treatment, published between 1995 and 2002. Estimates of life years gained were extracted and compared with estimates calculated using the Dutch male life table of 1996-2000.

RESULTS

Of the seven primary modelling analyses, six showed all the essential data. They estimated that 3 to 5.6 years (average 4.6 years) of statin treatment resulted in 0.15 to 0.41 years (average 0.3 years) saved over a lifetime time horizon. In contrast none of the 12 secondary modelling studies provided transparent results. They assumed lifelong treatment, leading to life table estimations of 2.4 and 2.0 (undiscounted) years saved for 40 and 60 year olds, with peak savings at around the mean age of death: 75-80 years. With 5% discounting, these effects reduced to 0.4 and 0.8 years respectively.

CONCLUSION

Reporting of essential data and assumptions on statin treatment was poor for secondary modelling analyses and satisfactory for primary modelling studies. Secondary modeling studies made assumptions on long term effectiveness that were hard to justify with the available evidence, and that led to the majority of life years saved at high ages. Further standardisation in economic analyses is important to guarantee transparency and reproducibility of results.

Surveillance and treatment of dyslipidemia in the post-infarct patient: can a nurse-led management approach make a difference?

BACKGROUND

Lowering plasma lipid levels in patients in the months following hospital discharge for a myocardial infarction (MI) is clearly beneficial if recurrent cardiac events and mortality are to be prevented; traditionally, however, there has been a large gap between guidelines and levels achieved in routine practice.

OBJECTIVES AND METHODS

A randomized, open-label clinical trial was conducted to assess the impact of nurse-centred surveillance and treatment in achieving nationally recognized lipid targets in post-MI patients. This program had the following features: systematic telephone follow-up of patients discharged from the University of Sherbrooke (Sherbrooke, Quebec) after an MI; systematic lipid testing three months after discharge; close liaison with, and guidance of, patients' primary care physicians to intervene on results of this test if targets were not obtained; and continued monitoring of patients until lipid profiles consistent with consensus targets were achieved. The impact of this approach was tested and compared with that of a control group that continued to be followed by a primary care physician for up to 18 months.

RESULTS

A total of 127 patients were randomly assigned into an intervention group (n=64) or a control group (n=63). The intervention group was followed by telephone for an average (+/-SD) of 4.4+/-2.0 months post-MI. At this point, when intervention was optimized, the mean low-density lipoprotein cholesterol (LDL-C) level was 2.19+/-0.65 mmol/L in the intervention group, and 87.3% of patients had LDL-C levels of less than 2.5 mmol/L. Patients from both experimental groups returned at 12 months and 18 months post-MI for a new blood lipid assessment. In total, 12.5% of patients in each group were lost to follow-up. At 12 months and 18 months, the mean LDL-C level was not different between the two groups, nor was there a significant difference in the proportion of patients achieving LDL-C levels of less than 2.5 mmol/L (51.6% in the intervention group and 65% in the control group at 18 months; P>0.05). When the combined end point of an LDL-C level of less than 2.5 mmol/L, a triglyceride level of less than 2.0 mmol/L and a total cholesterol to high-density lipoprotein cholesterol ratio of less than 4.0 was considered, the proportion of patients achieving this composite at 18 months was low and not different between the two groups (23.4% in the intervention group and 38.3% in the control group; P>0.05). Over 95% of patients in both groups were on a lipid-lowering medication, and more than 90% had complied with their medication regimen at 18 months.

CONCLUSIONS

This trial did not support the role of nurse-managers and a system of telephone-based contacts to ensure the continuity of care and aggressive intervention when considering cardiovascular risk factors in post-MI patients. This trial also re-emphasized the important remaining treatment gap in secondary prevention of coronary artery disease, particularly if composite lipid end points are to be targeted.

Coronary heart disease policy models: a systematic review

BACKGROUND

The prevention and treatment of coronary heart disease (CHD) is complex. A variety of models have therefore been developed to try and explain past trends and predict future possibilities. The aim of this systematic review was to evaluate the strengths and limitations of existing CHD policy models.

METHODS

A search strategy was developed, piloted and run in MEDLINE and EMBASE electronic databases, supplemented by manually searching reference lists of relevant articles and reviews. Two reviewers independently checked the papers for inclusion and appraisal. All CHD modelling studies were included which addressed a defined population and reported on one or more key outcomes (deaths prevented, life years gained, mortality, incidence, prevalence, disability or cost of treatment).

RESULTS

In total, 75 articles describing 42 models were included; 12 (29%) of the 42 models were micro-simulation, 8 (19%) cell-based, and 8 (19%) life table analyses, while 14 (33%) used other modelling methods. Outcomes most commonly reported were cost-effectiveness (36%), numbers of deaths prevented (33%), life-years gained (23%) or CHD incidence (23%). Among the 42 models, 29 (69%) included one or more risk factors for primary prevention, while 8 (19%) just considered CHD treatments. Only 5 (12%) were comprehensive, considering both risk factors and treatments. The six best-developed models are summarised in this paper, all are considered in detail in the appendices.

CONCLUSION

Existing CHD policy models vary widely in their depth, breadth, quality, utility and versatility. Few models have been calibrated against observed data, replicated in different settings or adequately validated. Before being accepted as a policy aid, any CHD model should provide an explicit statement of its aims, assumptions, outputs, strengths and limitations.

Cost effectiveness of statins in coronary heart disease

INTRODUCTION

Statin therapy reduces the rate of coronary heart disease, but high costs in combination with a large population eligible for treatment ask for priority setting. Although trials agree on the size of the benefit, economic analyses of statins report contradictory results. This article reviewed cost effectiveness analyses of statins and sought to synthesise cost effectiveness ratios for categories of risk of coronary heart disease and age.

METHODS

The review searched for studies comparing statins with no treatment for the prevention of either cardiovascular or coronary heart disease in men and presenting cost per years of life saved as outcome. Estimates were extracted, standardised for calendar year and currency, and stratified by categories of risk, age, and funding source

RESULTS

24 studies were included (from 50 retrieved), yielding 216 cost effectiveness ratios. Estimated ratios increase with decreasing risk. After stratification by risk, heterogeneity of ratios is large varying from savings to $59 000 per life year saved in the highest risk category and from 6500 dollars to 490,000 dollars in the lowest category. The pooled estimates show values of 21571 dollars per life year saved for a 10 year coronary heart disease risk of 20% and 16862 dollars per life year saved for 10 year risk of 30%.

CONCLUSION

Statin therapy is cost effective for high levels of risk, but inconsistencies exist at lower levels. Although the cost effectiveness of statins depends mainly on absolute risk, important heterogeneity remains after adjusting for absolute risk. Economic analyses need to increase their transparency to reduce their vulnerability to bias and increase their reproducibility.

Lipids and stroke: the opportunity of lipid-lowering treatment

Dyslipemia is a clear risk factor (RF) for ischemic heart disease and peripheral artery disease, but its relation with ischemic stroke (IS) is not so clear. HMG-CoA reductase inhibitor drugs or statins (simvastatin, atorvastatin, pravastatin) reduce the relative risk of IS by between 18 and 51% in patients with IHD, in patients with high vascular disease risk and in hypertensive patients with other RFs, acute coronary syndrome, and type 2 diabetes mellitus. According to the guidelines for use, statins are indicated in the majority of patients with IS since the risk is equivalent to that of IHD or high vascular disease risk. In view of the existing clinical evidence of benefit, it would not seem unreasonable to proceed with treatment of patients using statins while awaiting specific studies justifying their use. The non-lipid-lowering mechanisms of the statins and results of studies, such as the Heart Protection Study, provide evidence for widening the indications of statins beyond the prevention of dyslipemia, as a new therapeutic approach in the prevention of IS in patients with plasma levels of total cholesterol or low density lipoproteins currently considered within the normal distribution. The neuroprotective role, which these drugs may play in the acute phase of cerebral ischemia, remains to be clarified, but very recent evidence suggests that such patients may also benefit.

Cost-effectiveness of HMG-CoA reductase inhibitors in the treatment of dyslipidemia and prevention of CHD

The recent completion of several clinical trials of lipid-lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A inhibitors, or statins, was followed by an update in 2004 concerning the Adult Treatment Panel III guidelines issued by the National Cholesterol Education Program. Within this update, individuals considered at very high risk for coronary heart disease-related events were addressed, wherein the role of an aggressive, intensive lowering of lipid levels to new goals was presented. In achieving target cholesterol levels, the statins collectively represent first-line pharmacotherapeutic strategies, although each of the currently marketed agents differ in relative potency, dose, side effects and cost. As such, research concerning the pharmacoeconomics of lipid-lowering therapy may serve to augment clinical, evidence-based approaches to care. Furthermore, identifying and rectifying suboptimal care within healthcare systems may afford optimal outcomes amongst patients for resources consumed.

The evolving use of cost-effectiveness analysis in formulary management within the Department of Veterans Affairs

The Veterans Health Administration (VHA) runs the largest integrated healthcare system in the nation. Formulary management within VHA primarily involves 3 national groups: the Medical Advisory Panel, the Veterans Integrated Service Network Formulary Leaders, and the Pharmacy Benefits Management Strategic Healthcare Group. Together, these groups manage the VHA national drug formulary with a goal of providing a comprehensive, safe, and cost-effective pharmacy benefit for veterans. Traditionally, VHA has relied on cost-minimization analyses in formulary decisions. More recently, VHA has emphasized the use of cost-effectiveness data, especially for newer, costly drugs. In addition to including this data in drug monographs, the VHA has begun requiring formal cost-effectiveness analysis from manufacturers of selected pharmaceuticals. VHA has also requested that clinically relevant information such as quality of life plus mortality benefit be made available from industry so that internal cost analyses can be performed. It is hoped that by setting the expectation that cost-effectiveness will be formally considered in all VHA formulary decisions, the pharmaceutical industry and others will be stimulated to collect and report data that enables these analyses. We believe that if other organizations also place an emphasis on economic evaluations, industry and the public will be more accepting of decisions that incorporate cost considerations.

Persistence and determinants of statin therapy among middle-aged patients for primary and secondary prevention

AIMS

Statins have been shown to significantly reduce morbidity and mortality in patients with coronary artery disease (CAD), and also in patients with dyslipidaemia when statins are taken regularly. Middle-aged patients have the highest level of forecasting benefit and little is known about persistence rate of these therapies in a real-life setting. The objective was to evaluate the persistence rate of middle-aged patients initiating a statin therapy and its relation with several determinants for primary and secondary prevention.

METHODS

A cohort was reconstructed using the RAMQ databases. All patients aged 50-64 years-old who received at least one statin prescription between 1 January, 1998 and 31 December, 2000 for a new intention of treatment for dyslipidaemia were included in the cohort and followed up until 30 June, 2001. The date of the first prescription of statin was defined as the index date. There were 4316 patients in the secondary prevention (CAD diagnosis) and 13,642 patients in primary prevention cohort. The cumulative persistence rate was estimated using Kaplan-Meier, and Cox regression models were used to estimate the hazard ratio of ceasing statins.

RESULTS

We found that persistence with statins had fallen to 71% after 6 months of treatment, and had declined to 45% after 3 years in the secondary prevention cohort; the corresponding figures were 65% and 35% in the primary prevention cohort. Our results suggest that patients with dyslipidaemia in primary prevention compared with those in secondary prevention (HR: 1.18; 1.11-1.25) are less likely to be persistent. Patients with other cardiovascular risk factors such as age (HR: 0.99; 0.98-0.99), diabetes (HR: 0.84; 0.79-0.90), hypertension (HR: 0.76; 0.72-0.80) were most likely to be persistent with statins. We observed lower persistence in patients who have used the greatest number of pharmacies and prescribing physicians.

CONCLUSION

This analysis indicates that barriers to persistence occur early in the therapeutic course. Overall persistence with statins is low, and particularly among patients with few other cardiovascular risk factors.

Treating Osteoarthritis With Cyclooxygenase-2–Specific Inhibitors

Osteoarthritis and hypertension are highly prevalent among older Americans. Anti-inflammatory medications can destabilize blood pressure control. We estimated the decreased cardiovascular risk, premature mortality, and direct health care costs that could be avoided if blood pressure control is not destabilized among hypertensive Americans taking cyclooxygenase-2 (COX-2)-specific inhibitors for osteoarthritis. Data from the Third National Health and Nutrition Examination Survey (NHANES III) provided the distribution of cardiovascular risk factors among American adults with osteoarthritis and hypertension. The Cardiovascular Disease Life Expectancy Model was used to estimate the impact of a 2.26% increase in systolic blood pressure on the basis of results of a randomized trial comparing COX-2-specific inhibitors. A similar analysis was completed for American adults with osteoarthritis and untreated hypertension (> or =140/90 mm Hg). Among 7.3 million Americans with treated hypertension, maintaining blood pressure control would avoid >30,000 stroke deaths and 2,000 coronary deaths resulting in >449,000 person years of life saved and 1.4 billion dollars in direct health care cost savings. When an additional 3.8 million Americans with untreated hypertension are considered, maintaining blood pressure control could prevent >47,000 stroke deaths, 39,000 coronary deaths, and result in 668,000 person years of life saved and >2.4 billion dollars in direct health care cost savings. We conclude that even a small increase in systolic blood pressure among hypertensive Americans with osteoarthritis may substantially increase the clinical and economic burden of cardiovascular disease. Maintaining blood pressure control may be associated with substantial benefits.

Statin therapy in the elderly

PURPOSE OF REVIEW

The clinical efficacy and safety of statin therapy have been well established from a series of large-scale, randomized controlled trials. These trials, however, have predominantly recruited patients under the age of 70 years. As a consequence, the use of statins in older patients has remained controversial.

RECENT FINDINGS

The results of the first trial to look exclusively at the elderly--the Prospective Study of Pravastatin in the Elderly at Risk--have added enormously to our understanding of the use of statins in the elderly. These findings, together with those from the large elderly cohort within the Heart Protection Study and the smaller elderly subgroups within the other major statin trials, have forced us to re-evaluate any systematic exclusion of elderly patients from statin therapy.

SUMMARY

The collective evidence now strongly supports the use of statins in the at-risk elderly population.

The care gap: underuse of statin therapy in the elderly

Atherosclerotic diseases are responsible for the majority of deaths in the elderly, and they can also increase the risk of disability. Statins are first-line therapies for lowering lipid levels and have been shown to reduce the risk of cardiovascular events in large-scale clinical trials. There is a growing body of evidence that statins are as efficacious at lowering lipid levels and reducing the risk of coronary heart disease (CHD) in elderly patients as in younger individuals. Furthermore, as this population is at a greater absolute risk of CHD, they may receive greater absolute benefits from treatment. However, despite these benefits, many elderly individuals at risk of CHD and stroke are not receiving adequate lipid-lowering therapy, which could help them to maintain their health and independence. Further, prospective randomised trials are required to guide physicians in the treatment of elderly patients at risk of atherosclerotic disease, thereby resolving the current undertreatment.

Cost effectiveness of HMG-CoA reductase inhibitors in the management of coronary artery disease: the problem of under-treatment

HMG-CoA reductase inhibitors significantly reduce the risk of coronary artery disease (CAD) events and CAD-related mortality in patients with and without established CAD. Consequently, HMG-CoA reductase inhibitors have a central role within recommendations for lipid-modifying therapy. However, despite these guidelines, only one-third to one-half of eligible patients receive lipid-lowering therapy and as few as one-third of these patients achieve recommended target serum levels of low density lipoprotein-cholesterol. The underuse of HMG-CoA reductase inhibitors in eligible patients has important implications for mortality, morbidity and cost, given the enormous economic burden associated with CAD; direct healthcare costs, estimated at US $16-53 billion (2000 values) in the US and 1.6 billion pound (1996 values) in the UK alone, are largely driven by inpatient care. Hospitalization costs are reduced by treatment with HMG-CoA reductase inhibitors, particularly in high-risk groups such as patients with CAD and diabetes mellitus in whom net cost savings may be achieved. HMG-CoA reductase inhibitors are underused because of institutional factors and clinician and patient factors. Also, the vast number of patients eligible for treatment means that the use of HMG-CoA reductase inhibitors is undoubtedly limited by budgetary considerations. Secondary prevention in CAD using HMG-CoA reductase inhibitors is certainly cost effective. Primary prevention with HMG-CoA reductase inhibitors is also cost effective in many patients, depending upon CAD risk and drug dosage. As new, more powerful, HMG-CoA reductase inhibitors come to market, and the established HMG-CoA reductase inhibitors come off patent, the identification of the most cost-effective therapy becomes increasingly complex. Research in to the relative cost effectiveness of alternative HMG-CoA reductase inhibitors, taking full account of the institutional, clinician and patient barriers to uptake should be undertaken to identify the most appropriate role for the new therapies.

A pharmacoeconomic evaluation of the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study in the United Kingdom

OBJECTIVE

To determine the short-term healthcare costs associated with intensive lipid lowering with atorvastatin initiated within 24-96 hours of the occurrence of acute coronary syndrome (ACS) in patients in the UK.

METHODS

Patient-level clinical outcome data from the Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering (MIRACL) trial and standard cost data were used to compare the total expected 16-week cost per patient on atorvastatin 80 mg/day versus placebo. Clinical outcomes assessed included the following: death; cardiac arrest with resuscitation; nonfatal myocardial infarction; worsening angina pectoris with objective evidence of myocardial ischaemia requiring rehospitalisation; surgical or percutaneous coronary revascularisation; nonfatal stroke; hospitalisation for angina without objective evidence of myocardial ischaemia; and new or worsening congestive heart failure requiring rehospitalisation. All relevant direct medical costs from the perspective of the NHS were considered.

RESULTS

The total expected cost was pound 784.05 per patient in the placebo cohort and pound 851.59 per patient in the atorvastatin cohort, resulting in an incremental cost of pound 67.54 per patient in the atorvastatin group. The cost per event avoided was pound 1762.04. A third of the cost of atorvastatin treatment was offset within 16 weeks by the cost savings resulting from the reduction in the number of events in the atorvastatin cohort compared with the placebo cohort.

CONCLUSION

The clinical benefits of short-term intensive atorvastatin treatment administered after ACS is attainable through a marginal increase in 'upfront' costs.

Treatment of the elderly with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors: focus on drug interactions

With the aging of the population, death from coronary heart disease (CHD) and stroke has become more prevalent. Cardiovascular disease (CVD) risk factors, such as hypertension, obesity, and diabetes mellitus increase with age as well. Recent secondary-prevention studies have established the positive effect of statins in decreasing the risk of CHD mortality through the lowering of cholesterol. Statins have an excellent safety record, at least with users under age 65, and provide a cheaper alternative to more costly medical options. The most serious side effect associated with their use is myopathy, which is infrequent. Drug interactions have been found with drugs that compete for the same CYP450 isoenzymes as statins. Several drugs have been shown to significantly inhibit the CYP3A4 pathway; in combination with statins such as lovastatin, simvastatin, atorvastatin, and cerivastatin, they have been shown to elevate serum concentrations of these statins, or may increase the risk of myopathy. Alternatively, other drugs can inhibit the CYP2C9 pathway and may elevate serum concentration of fluvastatin. Due to the number of medications the elderly receive, an understanding of the various metabolic pathways is of vital importance to minimize the potential for drug interactions. The elderly population, while at high risk for CVD, is currently undertreated. Statins can effectively lower low-density lipoprotein cholesterol levels and lessen the risk of CVD for this population.

Advantages of lipid-lowering therapy in cerebral ischemia: role of HMG-CoA reductase inhibitors

Dyslipemia as a risk factor for ischemic stroke and indications for statins in the prevention of ischemic stroke are revised. The role of cholesterol levels as a risk factor for ischemic stroke is controversial. This could be due to failures in the design of early epidemiological studies. Recent studies, however, do suggest a clearer risk relationship between cholesterol levels and ischemic stroke. Studies conducted on the prevention of ischemic heart disease (IHD) with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), using pravastatin and simvastatin, unequivocally show reductions in overall mortality, cardiovascular mortality, acute myocardial infarction and other coronary events. These studies show a reduction in the risk of ischemic stroke, and although relative risk reduction is great, absolute risk reduction is low; the reasons for this are analyzed. Apart from lipid mechanisms, statins act on the atheroma plaque; they have antithrombotic and possibly neuroprotecting properties. Statins reduce the number of strokes due to the decrease of atherothrombotic strokes, cardioembolic strokes secondary to IHD, and lacunar strokes related to atherothrombosis and probably to microatheromas. Although there are currently no specific studies available on the secondary prevention of stroke with statins, which are required to clarify certain points, according to European and American guidelines for prevention, statins would be indicated in the secondary prevention of atherothrombotic stroke, and in cardioembolic and lacunar stroke associated with clinical or silent atherosclerosis (IHD, peripheral artery disease). Patients with ischemic stroke of other etiologies, except for stroke in the young or other unusual causes, are patients with a high vascular risk (cardiac and cerebral) owing to the stroke itself, age and other vascular risk factors, and they should also be treated with statins, at least from the point of view of primary prevention of IHD. Natural statins (pravastatin and simvastatin) play an essential part in secondary prevention of ischemic stroke, together with antiaggregants, anticoagulants, angiotensin-converting enzyme inhibitors and the treatment of other vascular risk factors.

Pharmacology and clinical experience with simvastatin

Simvastatin (Zocortrade mark, Merck) is a safe and effective 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Simvastatin potently lowers total and low density lipoprotein (LDL) cholesterol. Simvastatin was the first cholesterol-lowering agent that reduced total mortality in a randomised clinical trial. Simvastatin is effective at reducing total mortality, myocardial infarction, coronary mortality and the incidence of stroke or transient ischemic attack in patients with coronary heart disease and hypercholesterolemia. Simvastatin, like other statins, also has non-lipid mechanisms of action. These include anti-inflammatory effects, antiproliferative effects on smooth muscle cells and an upregulation of endothelial nitric oxide synthase. Overall, simvastatin has an excellent safety profile. Simvastatin, along with other statins, has made a significant impact on the morbidity and mortality from coronary heart disease.

How cost-effective is the treatment of dyslipidemia in patients with diabetes but without cardiovascular disease?

OBJECTIVE

Epidemiological studies have shown that the risk of myocardial infarction (MI) in diabetic patients without cardiovascular disease (CVD) is comparable to the risk of MI in patients with CVD. We used a validated Markov model to compare the long-term costs and benefits of treating dyslipidemia in diabetic patients without CVD versus treating CVD patients without diabetes in the U.S. The generalizability and robustness of these results were also compared across six other countries (Canada, France, Germany, Italy, Spain, and the U.K.).

RESEARCH DESIGN AND METHODS

With use of the Cardiovascular Disease Life Expectancy Model, cost effectiveness simulations of simvastatin treatment were performed for men and women who were 40-70 years of age and had dyslipidemia. We forecast the long-term risk reduction in CVD events after treatment. On the basis of the Scandinavian Simvastatin Survival Study results, we assumed a 35% reduction in LDL cholesterol and an 8% rise in HDL cholesterol.

RESULTS

In the U.S., treatment with simvastatin for CVD patients without diabetes was cost-effective, with estimates ranging from $8,799 to $21,628 per year of life saved (YOLS). Among diabetic individuals without CVD, lipid therapy also appeared to be cost-effective, with estimates ranging from $5,063 to $23,792 per YOLS. In the other countries studied, the cost effectiveness of treating diabetes in the absence of CVD was comparable to the cost effectiveness of treating CVD in the absence of diabetes.

CONCLUSIONS

Among diabetic men and women who do not have CVD, lipid therapy is likely to be as effective and cost-effective as treating nondiabetic individuals with CVD.

Standardization of lipoprotein reporting

We wanted to ascertain whether the current format of lipid laboratory reports seemed adequate to promote identification and treatment of patients with dyslipidemia. In a random survey of lipid laboratory reports from 25 laboratories, we found great inconsistencies among reporting formats and contents. Fewer than half the laboratories correctly reported the ranges for cholesterol, only 4 correctly reported ranges for high-density lipoprotein cholesterol, only 2 correctly reported ranges for triglycerides, and none presented low-density lipoprotein cholesterol ranges in terms of risk factors for coronary heart disease. Reports typically were disjointed and difficult to read. The current practice of reporting results for lipid panels is confusing and does not follow the National Cholesterol Education Program (NCEP) guidelines. We recommend that reporting of results be standardized, and a "model" standardized report is presented herein, based on consensus from a team of experts. The standardized report uses current recommendations for ranges, follows the flowcharts of the NCEP guidelines, and takes the patient's clinical condition (the number of risk factors and the presence of coronary heart disease) into consideration. Standardizing lipid reports should decrease confusion and perhaps increase application of the guidelines and patient compliance with treatment.

Hyperlipidemia

Coronary heart disease (CHD) is prevalent and often related to an unhealthy diet and hyperlipidemia. The diagnosis of hyperlipidemia should be carefully made, using more than one measurement in the manner described. An assessment of risks allows one to decide whom to treat. Patients with CHD should be treated aggressively but it is less clear how aggressive to be with patients without CHD. Diet and exercise recommendations are appropriate for almost all patients. For those for whom the benefit is greater than the potential risks, statins are first-line drug therapy and they appear to have beneficial effects aside from their lipid-lowering properties.

Cost-effectiveness of treating hyperlipidemia in the presence of diabetes : who should be treated?

BACKGROUND

The objective of this study was to estimate the long-term costs and benefits of treating hyperlipidemia among diabetic patients with and without known cardiovascular disease after validating the Cardiovascular Life Expectancy Model.

METHODS AND RESULTS

The model estimates were compared with the Scandinavian Simvastatin Survival Study (4S) and used to estimate the long-term costs and benefits of treatment with simvastatin. Simulations were performed for men and women, 40 to 70 years of age, having pretreatment LDL cholesterol values of 5.46, 4.34, and 3.85 mmol/L (211, 168, and 149 mg/dL). We forecasted the long-term risk of cardiovascular events, the need for medical and surgical interventions, and the associated costs in 1996 US dollars. The model validated well against the observed results of the of the 4S diabetic patients. In this validation, the model estimates fell within the 95% confidence interval of the observed results for 7 of the 8 available end points (coronary deaths, total deaths, and so forth). Treatment with simvastatin for patients with cardiovascular disease is cost-effective for men and women, with or without diabetes. Among diabetic individuals without cardiovascular disease, the benefits of primary prevention were also substantial and the cost-effectiveness ratios attractive across a wide range of assumptions ( approximately $4000 to $40 000 per year of life saved). These conclusions were robust even among diabetics with lower baseline LDL values and smaller LDL reductions as observed in the Cholesterol and Recruitment Events (CARE) trial.

CONCLUSIONS

Among adults with hyperlipidemia, the presence of diabetes identifies men and women among whom lipid therapy is likely to be effective and cost-effective even in the absence of other risk factors or known cardiovascular disease.

Cost-effectiveness of statins

The efficacy of lipid-lowering with statins has become clear. Indirect estimations, and direct measurements from long-term randomized trials have also demonstrated cost-effectiveness, both in secondary and primary prevention of coronary heart disease. Targeting care efficiently to high-risk groups by calculating absolute risk is essential. However, it is clear that what would normally be very cost-effective interventions will put substantial strain on health care resources because of the common nature of coronary disease and risk factors.

Reasons for noncompliance with infection control guidelines

Concern frequently is voiced about individuals not complying with guidelines intended to prevent spread of antibiotic-resistant pathogens from patient to patient, but institutional decisions to ignore Centers for Disease Control and Prevention guidelines recommending detection and isolation of colonized patients also have contributed greatly to the increasing rate of infections due to these pathogens. This is so because colonized patients are the main reservoir for spread, and barrier precautions prevent spread much more effectively than Standard Precautions. Providing effective leadership and changing this culture of noncompliance must begin with the infection control team believing that spread is both important and preventable.

Cost-effectiveness of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor therapy in older patients with myocardial infarction

BACKGROUND

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy has proven efficacy in reducing the rate of coronary and cerebrovascular events in patients 75 years of age or younger with a history of myocardial infarction. However, in patients older than 75 years of age, the efficacy and potential cost-effectiveness of statins are unknown.

OBJECTIVE

To estimate the incremental cost-effectiveness of statin therapy compared with usual care in patients 75 to 84 years of age with previous myocardial infarction.

DESIGN

Cost-effectiveness analysis.

DATA SOURCES

Published data from cohort studies.

TARGET POPULATION

Patients 75 to 84 years of age with a history of myocardial infarction.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

Statin therapy.

OUTCOME MEASURES

Life expectancy, quality-adjusted life expectancy, and incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

The incremental cost-effectiveness of statin therapy compared with usual care in patients 75 to 84 years of age with previous myocardial infarction was $18800 per quality-adjusted life-year (QALY).

RESULTS OF SENSITIVITY ANALYSIS

On the basis of a probabilistic sensitivity analysis, there is a 75% chance that statin therapy costs less than $39800 per QALY compared with usual care. If the cost of statin therapy and efficacy of statin therapy at reducing myocardial infarction were set to their most favorable values, statin therapy cost $5400 per QALY; if cost and efficacy were set to their least favorable values, statin therapy cost $97800 per QALY.

CONCLUSIONS

The cost-effectiveness ratios of statin therapy in older patients with previous myocardial infarction are reasonable under a wide variety of assumptions about drug efficacy, drug cost, and rates of cardiac and cerebrovascular events. Pending results of randomized, controlled trials of secondary prevention in patients in this age group, statin therapy seems to be as cost-effective as many routinely accepted medical interventions in this setting.

The cost-effectiveness of exercise training for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Although exercise training improves cardiovascular disease (CVD) risk factors, few studies have evaluated its potential long-term cost-effectiveness.

METHODS

Using the Cardiovascular Disease Life Expectancy Model, a validated disease simulation model, we calculated the life expectancy of average 35- to 74-year-old Canadians found in the 1992 Canadian Heart Health Survey. The impacts of exercise training on cardiovascular risk factors were estimated as a 4% decrease in low-density lipoprotein (LDL) cholesterol, a 5% increase in high-density lipoprotein (HDL) cholesterol, and a 6 mm Hg decrease in both systolic and diastolic blood pressure. Exercise adherence was estimated at 50% for the first year and 30% for all additional years. Costs for a supervised exercise program determined from Canadian sources and converted to US dollars were estimated at $605 for the first year (medical evaluation, stress test, exercise prescription, and program costs) and $367 for all additional years (program costs). For an unsupervised program, the costs were estimated at $311 for the first year and $73 for all additional years.

RESULTS

The cost-effectiveness (CE) of an unsupervised exercise program (1996 U.S. dollars) was less than $12,000 per year of life saved (YOLS) for all individuals. The CE of a supervised exercise program was less than $15,000/YOLS for men with CVD, and between $12,000 and $43,000 for women with CVD and men without CVD.

CONCLUSIONS

Given the relatively few risks, substantial long-term benefits, and modest costs, an unsupervised exercise training program represents good value for all. A more expensive supervised exercise program is also cost-effective for most individuals with CVD.

Optimizing treatment of dyslipidemia in patients with coronary artery disease in the managed-care environment (the Rocky Mountain Kaiser Permanente experience)

Rocky Mountain Kaiser Permanente has taken aggressive steps to ensure optimal treatment of all modifiable cardiac risk factors, especially low-density lipoprotein (LDL) cholesterol, in patients with coronary artery disease. In this article, we are presenting (1) the basic rationale for our approach, (2) the critical steps translating philosophy into practice, and (3) justification for all health plans to pursue a similar course. The continuum of physician-directed disease management systems that have evolved in our region-one administered by cardiology nurses in the perihospitalization period and the other by pharmacists in the long-term, outpatient setting-is then detailed. Although the relatively short duration that our comprehensive systems have been in place precludes any assessment of their impact on cardiac death, coronary artery disease events, or coronary artery disease procedure rates, the improvements in intermediate surrogate outcomes are promising. Virtually all surveyed patients participating in our management systems have been "very" or "extremely" satisfied with their experience. The LDL-cholesterol screening rate in the approximately 2,500 participants in the programs to date has reached 97%. Of these patients, 84% have LDL cholesterol <130 mg/dL and 48% <100 mg/dL, and only 15% of those few with LDL cholesterol >130 mg/dL (2.5% overall) are currently not receiving lipid-lowering therapy. The proportions of patients on aspirin/antiplatelet and beta-blocker therapy after myocardial infarction are 97% and 92%, respectively. The lipid-screening and treatment rates, especially, represent significant improvement from our own baseline, and compare favorably with outcomes from other practice settings. In conclusion, health maintenance organizations have tremendous incentive and the unique opportunity and ability to develop systems to better manage large numbers of individuals with coronary artery disease.

Secondary prevention in a cardiology group practice and hospital setting after a heart-care initiative

The American Heart Association (AHA) Consensus Panel Statement for Preventing Heart Attack and Death in Patients with Coronary Disease provides recommendations for the secondary prevention of heart disease in at-risk patients. Blackstone Cardiology Associates of Pawtucket, Rhode Island, undertook an initiative in their practice implementing secondary-prevention guidelines in patients with coronary artery disease. This retrospective study evaluates practice patterns for the management of hyperlipidemia for a cardiology group in an ambulatory and hospital setting after the institution of a physician-supervised, nurse-based disease management program. Practice patterns in patients with established coronary heart disease treated in a lipid center compared with non-lipid-center settings were evaluated. Parameters evaluated included documenting low-density lipoprotein (LDL) cholesterol, presence of lipid-lowering therapy, and achieving the National Cholesterol Education Program II (NCEP II) goal of LDL-cholesterol levels < or =100 mg/dL in patients with preexisting coronary artery disease. A total of 352 patients met inclusion criteria in the lipid-center setting and were compared with 289 non-lipid-center consecutively chosen patients. Age and gender differences were also evaluated. Inpatient medical records from a 254-bed Brown University-affiliated teaching hospital were also evaluated for lipid profile, achievement of NCEP II goal, and use of lipid-lowering medication on admission and discharge. The most recent LDL-cholesterol values of patients followed in the lipid-center and in the non-lipid-center setting of the Blackstone Cardiology Associates were compared. Blackstone Cardiology Associates consists of 4 cardiologists and 4 advanced-practice nurses. Achievement of LDL-cholesterol goal was higher in both the lipid-center and non-lipid-center settings compared with baseline. A smaller percentage of patients at goal in the lipid setting is likely due to referral bias resulting in patients with more difficult-to-manage mixed dyslipidemias and behavior-management issues ending up in the lipid center. There were no apparent sex differences at goal, and more elderly (age > or =65 years) achieved goal in the lipid clinic center. In the non-lipid-center setting, more males were at goal and had a lower mean LDL-cholesterol level.

Effects of statins on carotid disease and stroke

The results of recent trials indicate that statin treatment reduces not only the risk of coronary heart disease, but also the risk of stroke, in patients with existing heart disease. The need for the treatment of such patients is now generally recognized. Mechanisms for risk reduction include the retardation of plaque progression, plaque stabilization, and reducing the risk of coronary events. Questions remain regarding the discrepancy between epidemiological data and statin trials data, the precise mechanism of action of statins, and their role in the prevention of recurrent stroke in individuals who have experienced a previous stroke or transient ischemic attack but are free of coronary disease.