Economic evaluation of donepezil for the treatment of Alzheimer's disease in Canada

Where are we at with model-based economic evaluations of interventions for dementia? a systematic review and quality assessment

ABSTRACTObjective:To identify, review, and critically appraise model-based economic evaluations of all types of interventions for people with dementia and their carers.

DESIGN

A systematic literature search was undertaken to identify model-based evaluations of dementia interventions. A critical appraisal of included studies was carried out using guidance on good practice methods for decision-analytic models in health technology assessment, with a focus on model structure, data, and model consistency.

SETTING

Interventions for people with dementia and their carers, across prevention, diagnostic, treatment, and disease management.

RESULTS

We identified 67 studies, with 43 evaluating pharmacological products, 19 covering prevention or diagnostic strategies, and 5 studies reporting non-pharmacological interventions. The majority of studies use Markov models with a simple structure to represent dementia symptoms and disease progression. Half of all studies reported taking a societal perspective, with the other half adopting a third-party payer perspective. Most studies follow good practices in modeling, particularly related to the decision problem description, perspective, model structure, and data inputs. Many studies perform poorly in areas related to the reporting of pre-modeling analyses, justifying data inputs, evaluating data quality, considering alternative modeling options, validating models, and assessing uncertainty.

CONCLUSIONS

There is a growing literature on the model-based evaluations of interventions for dementia. The literature predominantly reports on pharmaceutical interventions for Alzheimer's disease, but there is a growing literature for dementia prevention and non-pharmacological interventions. Our findings demonstrate that decision-makers need to critically appraise and understand the model-based evaluations and their limitations to ensure they are used, interpreted, and applied appropriately.

A pharmacoeconomic evaluation of cholinesterase inhibitors and memantine for the treatment of Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) results in progressively worsening cognitive decline, leading to loss of functional ability, behavior/mood disturbances, institutionalization, and death. Current pharmaceutical therapies only treat the symptoms of cognitive decline yet can be expensive for payers. Areas covered: The authors undertook a systematic review of economic evaluations of pharmaceutical therapies for AD. The literature search encompassed English-language studies indexed in PubMed (Medline), Cochrane Library Current, and Web of Science. The search included articles published between 1 January 1995 and 10 February 2018. The literature suggested AD medications generally dominated comparator treatments (e.g. placebo). Expert opinion: The authors noted several limitations of the included economic evaluations. These limitations suggest the results of the economic evaluations should be interpreted with caution. Many economic models were not transparent with respect to sources of probabilities and cost data, and data collected in certain jurisdictions were applied to other jurisdictions without considering the validity of such applications. Measuring health utilities in cognitively impaired populations raises questions about the validity of quality-adjusted life years, but this issue was unaddressed in the included studies. Most included studies were sponsored by industry and the results tended to overwhelmingly support the manufacturer's product.

An Economic Analysis of the Management of Alzheimer's Disease in the United Kingdom

Alzheimer's disease is a chronic and progressive disorder mainly affecting people aged over 65 years. Dementia and Alzheimer's disease affect a substantial proportion of the UK population in this age group, and their number is expected to increase dramatically over the next 20 years. At the moment there is no cure for Alzheimer's disease, though people suffering from this disorder use a significant proportion of health and social services. The burden of dementia and Alzheimer's disease has been investigated in several studies. The recent introduction of new drugs for the treatment of Alzheimer's disease has increased the interest in managing the disease. However, the few studies to assess the value for money of these new treatments are ambiguous in their conclusions. More detailed analyses specifically comparing cost and outcomes associated to the use of alternative treatments for the management of people with Alzheimer's disease are therefore required.

A 10-year perspective on donepezil

INTRODUCTION

Donepezil is the first cholinesterase inhibitor widely used for the treatment of Alzheimer's disease (AD). Its pharmacological actions are straightforward, enhancing cholinergic activity both in the brain and systemically, with a long-enough half-life to allow for once a day dosing. Its efficacy has been approved for use in mild-to-moderate AD stage for improvement of symptoms for 10 years, and now it is also approved for use in severe stage.

AREAS COVERED

This review article will offer a 10-year perspective on the use of donepezil in clinical practice against AD and related disorders. In addition to discussing the information from randomized clinical trials and from the drug monograph, this article will seek to facilitate the clinical development and clinical use of the next generation of drugs for AD.

EXPERT OPINION

Adjustments about expectations and safe use of donepezil were made over time based on such clinical experiences. Offering a cholinesterase inhibitor to patients with mild-to-moderate AD clearly showed advantages. If well tolerated, donepezil should be continued in the severe stages of AD as long as the patient appears to benefit from a slower clinical decline.

Systematic review of economic evaluations of Alzheimer's disease medications

This systematic review was conducted to summarize published pharmacoeconomic studies of Alzheimer's disease (AD) medications. Pharmacoeconomic studies were included in the review if they were published in English and contained a full and complete report of an original economic evaluation. The studies also had to be comparative in nature (i.e., cost-benefit, cost-effectiveness, cost-utility or cost-minimization analyses). Existing AD medications were found to dominate standard treatment (i.e., no drugs), or they were found to be more costly and more effective than standard treatment. Estimates of cost and effect varied widely because of different underlying models, assumptions and data sources. More research is needed to draw firmer conclusions regarding the overall cost-effectiveness of AD medications.

Methodological considerations in cost of illness studies on Alzheimer disease

Cost-of-illness studies (COI) can identify and measure all the costs of a particular disease, including the direct, indirect and intangible dimensions. They are intended to provide estimates about the economic impact of costly disease. Alzheimer disease (AD) is a relevant example to review cost of illness studies because of its costliness.The aim of this study was to review relevant published cost studies of AD to analyze the method used and to identify which dimension had to be improved from a methodological perspective. First, we described the key points of cost study methodology. Secondly, cost studies relating to AD were systematically reviewed, focussing on an analysis of the different methods used. The methodological choices of the studies were analysed using an analytical grid which contains the main methodological items of COI studies. Seventeen articles were retained. Depending on the studies, annual total costs per patient vary from $2,935 to $52, 954. The methods, data sources, and estimated cost categories in each study varied widely. The review showed that cost studies adopted different approaches to estimate costs of AD, reflecting a lack of consensus on the methodology of cost studies. To increase its credibility, closer agreement among researchers on the methodological principles of cost studies would be desirable.

Pharmacoeconomics of Alzheimer's disease (AD) treatment with cholinesterase inhibitors

Until more effective and especially disease-modifying treatments for Alzheimer's disease (AD) are available, the therapeutic arsenal consists of cholinesterase inhibitors for mild to moderate dementia and memantine for moderate to severe dementia. Health economic data make an important contribution to the planning of healthcare services and the estimation of the cost of drug reimbursement. As such, for cholinesterase inhibitors it is claimed that the direct cost of the drug itself is eclipsed by the cost savings associated with delaying institutionalisation or delaying the time of progression into a more severe disease state. The present manuscript reviews several factors contributing to the costs of AD, gives an overview of available studies claiming the cost-effectiveness of current AD treatments, highlights strengths and weaknesses of the aforementioned studies, and discusses the impact of (early) identification and treatment of AD. It is concluded that there still is a need for long-term follow-up data from prospective cohort studies before the cost-effectiveness of cholinesterase inhibitors for AD can be confirmed.

Evaluating the cost effectiveness of donepezil in the treatment of Alzheimer's disease in Germany using discrete event simulation

BACKGROUND

Previous cost-effectiveness studies of cholinesterase inhibitors have modeled Alzheimer's disease (AD) progression and treatment effects through single or global severity measures, or progression to "Full Time Care". This analysis evaluates the cost-effectiveness of donepezil versus memantine or no treatment in Germany by considering correlated changes in cognition, behavior and function.

METHODS

Rates of change were modeled using trial and registry-based patient level data. A discrete event simulation projected outcomes for three identical patient groups: donepezil 10 mg, memantine 20 mg and no therapy. Patient mix, mortality and costs were developed using Germany-specific sources.

RESULTS

Treatment of patients with mild to moderately severe AD with donepezil compared to no treatment was associated with 0.13 QALYs gained per patient, and 0.01 QALYs gained per caregiver and resulted in average savings of €7,007 and €9,893 per patient from the healthcare system and societal perspectives, respectively. In patients with moderate to moderately-severe AD, donepezil compared to memantine resulted in QALY gains averaging 0.01 per patient, and savings averaging €1,960 and €2,825 from the healthcare system and societal perspective, respectively.In probabilistic sensitivity analyses, donepezil dominated no treatment in most replications and memantine in over 70% of the replications. Donepezil leads to savings in 95% of replications versus memantine.

CONCLUSIONS

Donepezil is highly cost-effective in patients with AD in Germany, leading to improvements in health outcomes and substantial savings compared to no treatment. This holds across a variety of sensitivity analyses.

Assessing the cost-effectiveness of the rivastigmine transdermal patch for Alzheimer's disease in the UK using MMSE- and ADL-based models

OBJECTIVE

Assess long-term cost-effectiveness of rivastigmine patch in Alzheimer's disease (AD) management in the UK, using cognitive and functional models based on clinical trial efficacy data.

METHODS

Incremental costs and Quality Adjusted Life Years (QALYs) associated with rivastigmine patch and capsule treatment versus best supportive care (BSC) were calculated using two economic models, one based solely on Mini-Mental State Examination (MMSE) scores, and one also incorporating activities of daily living (ADL) scores. The clinical pathway was populated with data from a clinical trial of rivastigmine patch (9.5 mg/24 h) and capsules (12 mg/day) versus placebo. Costs were based on the UK health and social care costs and basic UK National Health Service (NHS) prices. Disease progression was modelled beyond the trial period over 5 years using published equations to predict natural decline in AD patients. Base case costing variables included drugs, clinical monitoring, and institutionalization.

RESULTS

The MMSE model estimated incremental costs per QALY of £10 579 for rivastigmine patch and £15 154 for capsule versus BSC. The MMSE-ADL model estimated incremental costs per QALY of £9114 for rivastigmine patch and £13 758 for capsules. The main difference between the models was a greater number of institutionalized days avoided for rivastigmine versus BSC estimated by the MMSE-ADL model.

CONCLUSIONS

Both the MMSE and MMSE-ADL models suggest that rivastigmine patch and capsules are cost-effective treatments versus BSC. Incorporating ADL evidence makes a marginal but important difference to estimates in this case. Future economic evaluations of AD treatment should include measures of both cognition and functioning.

Alzheimer's disease: the strength of association of costs with different measures of disease severity

OBJECTIVE

To identify Alzheimer's disease (AD) severity measures for use in cost-effectiveness models that effectively capture the impact of AD on costs.

METHODS

A review of the literature and data abstraction from papers that present 1) mean AD costs (direct, indirect, or total) by disease severity, defined using measure of cognition, functional status, and behavior; and/or 2) the results of regression analyses that estimate the strength of the association between AD costs and disease severity.

RESULTS

All papers reviewed showed that mean total costs increase with disease severity regardless of severity-measurement method. The relative difference in mean total costs between patients with severe disease compared to those with moderate disease, or moderate disease compared to mild disease, was fairly consistent across studies, suggesting that any of the disease-severity measures may be used to broadly categorize patients by cost. However, when regression analysis included multiple disease-severity measures, independent associations with costs were noted for the different measures. Cognitive and functional status measures were consistently associated with direct costs, whereas functional status and behavioral measures were consistently associated with indirect costs and caregiver hours.

CONCLUSIONS

Either multidimensional disease-severity measures, or a single disease-severity measure, that capture the impact of cognition, functional status, and behavior on costs are needed for cost-effectiveness models.

Savings from sub-groups?: Policy guidance and Alzheimer's disease treatments

BACKGROUND

A range of new therapeutic agents are now available for the management of Alzheimer's disease. With limited resources available however, policy-makers and other health care professionals have to prioritise and judge competing treatments on criteria such as the magnitude of clinical effectiveness and cost-effectiveness. Policy guidance that restricts treatments to defined patient sub-groups can improve the cost-effectiveness of treatments, and can help limit rises in health care expenditures. Budget impact models that estimate the amount of additional costs and potential savings are being increasingly used by policy-makers. However, the amount of savings estimated in such models depends on the effectiveness of treatment in changing morbidity, and the association between morbidity and costs.

AIM

To examine the magnitude of cost savings arising from provision of treatment to different patient sub-groups, using policy guidance decisions made by the National Institute for Health and Clinical Excellence (NICE) for cholinesterase inhibitor therapies in Alzheimer's Disease (AD) in the United Kingdom National Health Service (NHS).

METHOD

Cohort simulation modelling.

RESULTS

Policy guidance decisions that restricted treatment to smaller patient sub-groups were associated with lower overall care costs, but did not reduce drug costs.

CONCLUSIONS

Given increasing recognition by health policy-makers of the importance of affordability of new treatments, greater attention should be paid to measurement of cost impacts by sub-groups within health economic modelling.

Donepezil: A Review of Pharmacological Characteristics and Role in the Management of Alzheimer Disease

Donepezil is a potent, selective, noncompetitive, and rapidly reversible inhibitor of acetylcholinesterase (AChEI) licensed for the treatment of Alzheimer disease (AD); and is the first and only AChEI licensed for the treatment of severe AD. Its efficacy as monotherapy, or in combination with the NMDA-agonist, memantine, has been documented in several randomised double-blind, placebo-controlled, short-term clinical trials, as well as long-term extension trials and observational studies. Donepezil is a well tolerated drug that is generally safe as demonstrated even in patients with multiple co-morbidities receiving polypharmacy. It has been shown that donepezil improves cognition and global function in patients with mild-to-moderate AD; and long-term efficacy is maintained for up to 50 weeks. There is a dose-response relationship, with higher doses more likely to produce symptomatic benefit. Furthermore, donepezil-treated patients may improve cognitively and show global clinical improvement in all disease stages, including severe AD. Less consistent results in all disease stages were obtained on measures of function and behavior, and observations of mood. No effect on transition to AD has been found in long-term, randomized clinical trials in mild cognitive impairment (MCI). Cost-effectiveness of the treatment has been questioned by one long-term open-label societal study of 2-years duration. This study reported modest improvement of cognition but no statistically significant benefits during donepezil treatment as compared to placebo, in terms of rates of institutionalization and progression toward greater disability. However, there is a need for further research on clinically meaningful outcomes and treatment benefits favored by patients and caregivers, which are traditionally not defined as outcomes in clinical trials. Likewise, we need to know how to select responders, what is an optimal AChE inhibition particularly during the long-term treatment, in which patients the dosage should be increased for a sustained benefit, what is the optimal duration of treatment and when is meaningful to stop the treatment. After almost two decades of donepezil use in everyday clinical practice these issues are still unresolved.

Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model

Background

Alzheimer's Disease (AD) affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development.

Methods

A time-to-event (TTE) simulation provided estimates of screening asymptomatic patients in the general population age ≥55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death.

Results

The base case results indicated increased AD free years (AD-FYs) through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years) the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90).

Conclusions

This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials.

Commentary on "Health economics and the value of therapy in Alzheimer's disease." Cost-effectiveness studies

The high prevalence of dementia has a great impact on the formal care systems as well as on the situation for informal caregivers. Thus the question of cost effectiveness is crucial. This paper is based on the health-economic portion of the dementia project of the Swedish Council on Technology Assessment in Healthcare. After a database search and quality judgment of papers, 35 papers were included (22 were pharmacoeconomic studies, and 13 focused on programs, such as daycare, caregiver support, and living arrangements). No empirical drug study was regarded as a complete health-economic study. Of the four prospective, randomized, controlled trials, three yielded a nonsignificant difference regarding costs (all for donepezil), whereas there was a significant cost reduction in the Memantine study (favoring Memantine treatment), mainly due to reduction in caregiver time. The majority of the complete pharmacoeconomic modeling studies showed a dominance for drug treatment, indicating cost effectiveness. In conclusion, as regards the cost effectiveness of treatment for Alzheimer's disease, no evidence could be stated in terms of empirical studies, mainly because of a lack of studies. Although most models indicated cost effectiveness, the Swedish Council on Technology Assessment in Healthcare did not regard this as sufficient evidence of cost effectiveness. There is a need for larger and longer empirical studies, and for enlarged sensitivity analyses, in terms of model studies.

An estimate of the total worldwide societal costs of dementia in 2005

BACKGROUND

The aim of this report was to estimate the worldwide cost of dementia in 2005 from a societal viewpoint.

METHODS

Costs were estimated by combining prevalence estimates, country and region specific data on Gross Domestic Product per person, and average wage with results from previously published cost-of-illness studies in different countries. Direct medical and nonmedical costs as well as costs for informal care were included.

RESULTS

The total worldwide societal cost of dementia, on the basis of a dementia population of 29.3 million persons, was estimated to be US$315.4 billion in 2005, including US$105 billion for informal care (33%). Seventy-seven percent of the total costs occurred in the more developed regions, with 46% of the prevalence.

CONCLUSIONS

Worldwide costs for dementia are enormous, and informal care constitutes a major cost component, in particular in less developed regions. The health economics of dementia is a highly relevant area for further research.

Health economic effect of donepezil treatment for CDR 0.5 converters to Alzheimer's disease as shown by the Markov model

The previous health economic simulation of donepezil based on the Markov model revealed the treatment for mild to moderate stage of Alzheimer disease (AD) to be cost-effective. Our aim was to examine the economic effect of donepezil treatment for mild cognitive impairment, from which about 15% convert to dementia per year. We constructed a new Markov model using three simulations. Namely, Simulation A hypothesized that mild AD patients, i.e., Clinical Dementia Rating (CDR) 1, received donepezil as in the previous study. Simulation B hypothesized that all CDR 0.5 subjects received donepezil, and Simulation C considered that only the CDR 0.5 converters to dementia received donepezil. We calculated the models as follows: Simulation B, supposes that the annual transition probabilities were reduced even from 15% to 10% by donepezil, however, the drug had a negative economic effect. By contrast, in Simulation C, the annual transition probability was reduced from only 15% to 12% by donepezil, there was a positive economic effect. Since it is necessary to reduce the annual transition probability from 15% to 12% in order to manifest a concomitant economic benefit, we consider that early detection of CDR 0.5 converters in the community is important for health policy planning.

Decision analytic models for Alzheimer's disease: state of the art and future directions

Decision analytic policy models for Alzheimer's disease (AD) enable researchers and policy makers to investigate questions about the costs and benefits of a wide range of existing and potential screening, testing, and treatment strategies. Such models permit analysts to compare existing alternatives, explore hypothetical scenarios, and test the strength of underlying assumptions in an explicit, quantitative, and systematic way. Decision analytic models can best be viewed as complementing clinical trials both by filling knowledge gaps not readily addressed by empirical research and by extrapolating beyond the surrogate markers recorded in a trial. We identified and critiqued 13 distinct AD decision analytic policy models published since 1997. Although existing models provide useful insights, they also have a variety of limitations. (1) They generally characterize disease progression in terms of cognitive function and do not account for other distinguishing features, such as behavioral symptoms, functional performance, and the emotional well-being of AD patients and caregivers. (2) Many describe disease progression in terms of a limited number of discrete states, thus constraining the level of detail that can be used to characterize both changes in patient status and the relationships between disease progression and other factors, such as residential status, that influence outcomes of interest. (3) They have focused almost exclusively on evaluating drug treatments, thus neglecting other disease management strategies and combinations of pharmacologic and nonpharmacologic interventions. Future AD models should facilitate more realistic and compelling evaluations of various interventions to address the disease. An improved model will allow decision makers to better characterize the disease, to better assess the costs and benefits of a wide range of potential interventions, and to better evaluate the incremental costs and benefits of specific interventions used in conjunction with other disease management strategies.

How long can patients with mild or moderate Alzheimer's dementia maintain both the cognition and the therapy of cholinesterase inhibitors: a national population-based study

The aims of this study were to evaluate the duration of acetylcholinesterase inhibitors (AChEI) utilization as well as the patients' cognition maintenance. This study was using panel data from the Bureau of National Health Insurance (BNHI) of Taiwan from 2001 to 2004. Patients with mild or moderate AD were prescribed AChEI (donepezil, rivastigmine, or galantamine). By the regulation of BNHI, if the score of Mini-Mental Status Examination worsened by more than two points or clinical dementia rating (CDR) worsened by one or more grades in the follow-up every half year, the AChEI treatment would be terminated. Kaplan-Meier product-limit method was used to estimate duration of drug utilization. Regression model was performed to analyse the factors affecting the discontinuation of AChEI treatment. Our results showed female are more and younger than male in mild to moderate Alzheimer's dementia. The mean duration of use of AChEI was 432 days. Only 9.6% of patients maintained stable cognition tests results with continued drug refill for more than 3 years. Discontinuation rate in older patients (age > or =76 years) was higher than those in younger age (P = 0.0009). The average duration for AChEI therapy is around 14 months. The elderly are at high risk for treatment discontinuation.

Is long-term treatment of Alzheimer's disease with cholinesterase inhibitor therapy justified?

The cholinesterase inhibitors (ChEIs) donepezil, rivastigmine and galantamine are the current mainstays in the drug treatment of Alzheimer's disease (AD). There is convincing evidence that these agents provide at least modest cognitive, behavioural and functional benefit for 6-12 months at all stages of the disease. Longer term benefits cannot be directly examined by placebo-controlled trials. Nevertheless, the results of virtually all open-label extensions of the pivotal trials, studies of patients with AD at different levels of severity and clinical trials using other designs favour treatment over no treatment for periods of up to 5 years. There are plausible biological reasons why ChEIs might be expected to work over a prolonged period of time although, to date, studies using various markers to chart the effects of medication on long-term disease progression have yielded mixed results. The most contentious issue regarding long-term treatment is economic, but the majority of available economic analyses suggest net savings over the long term if patients with AD receive persistent treatment with ChEIs.

Cost-effectiveness analysis of donepezil for mild to moderate Alzheimer's disease in Taiwan

BACKGROUND

Donepezil is a drug used for treatment in patients with Alzheimer's disease (AD). Information regarding the cost-effectiveness of this medication was previously rare in Asia. We used techniques of decision analysis and economic evaluation in conjunction with available local epidemiological and clinical data on costs of mild to moderate AD to assess the cost-effectiveness of donepezil in Taiwan.

METHODS

A four-state Markov model was built to simulate the disease progression of AD patients. Local transition probabilities and costs of different stages were from the studies published earlier.

RESULTS

Over a 5-year span, donepezil treatment for mild or moderate AD patients is predicted to result in the gain of 0.505 QALYs when comparing to usual care, while at the same time reducing the cost by US$7,691. The incremental cost was US$3,647 from the payer perspective; thus, the incremental cost-effectiveness ratio was estimated to be US$7,226 when considering only the medical expenditures.

CONCLUSIONS

Under some assumptions, donepezil treatment might be a cost saving strategy for mild to moderate AD patients in Taiwan from a societal perspective. It is inconclusive from the payer's part since we still lack a consensus for judging the cost-effectiveness of a new health care technology.

Economic considerations in the management of Alzheimer's disease

Alzheimer’s disease is a devastating chronic disease that significantly increases healthcare costs and affects the quality of life (QoL) of the afflicted patients and their caregivers. Population aging and other demographic changes may further increase the already staggering costs of this devastating disease. While few pharmacoeconomic studies have used a prospective health economics design to assess resource utilization, most studies showed beneficial treatment effects and suggested potential savings in healthcare costs and reductions in caregiver burden. Various degrees of cost savings have been reported depending on the type of economic model, treatment evaluated, and region used in the studies. Direct comparisons of the results are difficult because different methods have been used in these evaluations. The preference of patients and families for home care for as long as possible suggests that promoting noninstitutional care for these patients should become a priority. Continued home care for patients under pharmacological treatment may reduce caregiver burden, healthcare costs, and ultimately improve patients’ and caregivers’ QoL.

Long-term cost-effectiveness of donepezil for the treatment of Alzheimer's disease

BACKGROUND

(Acetyl-)cholinesterase (ChE) inhibitors have been approved for the treatment of mild to moderate Alzheimer's disease (AD). However, use of ChE inhibitors is limited by budget constraints and disincentives on the side of health insurances and nursing care insurances.

OBJECTIVE

To analyse under what conditions the application of the acetylcholinesterase inhibitor donepezil is favourable for the treatment of patients with AD from the perspective of health insurance and nursing care insurance companies in Germany, taking into account factors such as start and duration of treatment, duration of follow-up, drug costs, internalization of opportunity costs and varying mortality and efficacy rates.

METHODS

Transition probabilities from a Swedish study and German cost data for donepezil were merged in a Markov model to follow a cohort of patients over a period of 5-10 years. We defined a base case with 1 year treatment and follow-up over 5 years and varied treatment length, follow-up interval and cost factors in sensitivity analyses.

RESULTS

In the base case, the ChE inhibitor donepezil did not lead to cost savings but to a cost-effective outcome on side of health insurances and nursing care insurances. Early treatment of AD and internalization of opportunity costs (caring time devoted to patients) led to less costs per quality adjusted life years gained. However, results are very sensitive with respect to varying mortality and efficacy rates.

CONCLUSION

The application of donepezil may be cost-effective, but considerable uncertainties remain. Moreover, the way the reimbursement system in Germany is presently arranged does not support the application of ChE inhibitors.

Economic cost of dementia patients according to the limitation of the activities of daily living in Korea

BACKGROUND

Dementia is expected to become a significant social burden in the future. However, there are few reports that have estimated the total economic cost of dementia, particularly according to the limitation in the activities of daily living (ADL) in Korea.

OBJECTIVES

This study is to analyze the health care expenditures and cost per dementia patient, and estimated the total economic cost of dementia.

METHODS

Caregivers of 609 dementia patients, who were randomly selected from a nationwide claim database of the Korean National Health Insurance Corporation, were interviewed using structured questionnaire in the period of September 2005. The total cost including the direct and indirect costs during a year was calculated. The patients were stratified into three limitation groups according to their ADL score. The cost according to the three limitation groups was analyzed. The national cost of dementia patients was then estimated.

RESULTS

The total cost per dementia patient in Korea was $7,462. The direct and indirect costs were $6,626 and $836 per patient, respectively. The cost increased with increasing degree of limitation in the patient's ADL. Over a 1-year period, the total cost per patient in the low limitation group was lower ($3,698) than that of the moderate ($6,064) and high ($11,428) limitation group.

CONCLUSIONS

This study demonstrates that the direct and indirect costs of dementia are considerately small for patients with lower limitation in their ADL. The total economic cost of dementia per year was estimated to be in the range of 1.3 to 3.3 billion dollars on assumptions in Korea.

Donepezil: an update

Donepezil hydrochloride is the most widely prescribed drug for Alzheimer's disease (AD). The main mechanism of action through which it influences cognition and function is presumed to be the inhibition of acetylcholinesterase enzyme in the brain; however, donepezil may also impact the pathophysiology of AD at several other points. Officially approved for mild-to-moderate and severe AD, donepezil has also been shown to be effective in early-stage AD, vascular dementia, Parkinson's disease dementia/Lewy body disease and cognitive symptoms associated with multiple sclerosis. In addition, one study suggested that donepezil may delay the onset of AD in subjects with mild cognitive impairment, a prodrome to AD. The pharmacokinetics, pharmacodynamics, safety/tolerability profile and drug interaction properties of donepezil make it an easy and safe agent to use. However, in general, the efficacy of donepezil is limited, and ongoing studies are investigating other agents that may ultimately overtake its present position as the mainstay of anti-AD therapy.

Modelling disease progression in Alzheimer's disease: a review of modelling methods used for cost-effectiveness analysis

The literature reporting economic evaluations related to the treatment of Alzheimer's disease (AD) has developed over the last decade. Most analyses have used economic models to estimate the cost effectiveness of drugs for the treatment of AD. This review considers the range of methods used in the published cost-effectiveness literature to model AD progression and the effect of interventions on the progression of AD. The review builds on and updates an earlier systematic review of cost-effectiveness studies on drugs for AD. Systematic and rigorous methods were used to search the literature for economic evaluations estimating the cost effectiveness of donepezil, rivastigmine, galantamine or memantine in AD. The literature search covered a wide range of electronic databases (e.g. MEDLINE, EMBASE), and included literature from the inception of databases up to the end of 2005. The search identified 22 published economic evaluations. An outline and brief critical review of the identified studies is provided, and thereafter the methods used to model disease progression were considered in more detail. The review employs recent guidance on good practice in decision-analytic modelling in HTA to critically review the modelling methods used. Using this guidance, the models are assessed against the broad criteria of model structure, data inputs and assessment of uncertainty and inconsistency. Concerns were noted over the model structure employed in all models. The reliance on cognitive scores to model AD, the progression of the disease, and the effect of treatment on costs and consequences is regarded as a serious limitation in almost all of the studies identified. There are also limitations over the data used to populate published models, especially around the failure of studies to document and establish the basis for the modelling of treatment effects. It is also clear that studies modelling AD progression, and subsequently the cost effectiveness of treatment, have not addressed uncertainty or consistency (internal and/or external) in sufficient detail. Further research is required on more appropriate methods for the modelling of AD progression. In the meantime, future economic evaluations of treatment need to be more explicit on the methods used to model AD, and the data used to populate models.

Principles for evidence-based drug formulary policy

Expenditures for prescription drugs continue to increase, prompting insurers and health systems to adopt formulary or coverage policies restricting the use of more expensive drugs. Those establishing formulary policies face a complex array of claims regarding differences in efficacy, safety, treatment cost, or cost-effectiveness. We describe and illustrate 5 specific principles for applying research evidence to formulary decisions: (1) Experimental data should take precedence over models or simulations, and assumptions of such models should be carefully examined. (2) Morbidity or mortality outcomes should take precedence over surrogate or intermediate outcomes. (3) Claims for advantages of new treatments should consider the full range of alternatives rather than those selected by industry. (4) Variation in effects across individuals or subgroups argue against restrictions on first-line treatment, but only if those differences are predictable. (5) Variation in effects argues against requiring changes in ongoing treatment. We also discuss how economic incentives are likely to influence selection of research questions, especially research related to drug-gene interactions and to identifying new indications for existing drugs.

Common Methodological Flaws in Economic Evaluations

Economic evaluations are increasingly being used by those bodies such as government agencies and managed care groups that make decisions about the reimbursement of health technologies. However, several reviews of economic evaluations point to numerous deficiencies in the methodology of studies or the failure to follow published methodological guidelines. This article, written for healthcare decision-makers and other users of economic evaluations, outlines the common methodological flaws in studies, focussing on those issues that are likely to be most important when deciding on the reimbursement, or guidance for use, of health technologies. The main flaws discussed are: (i) omission of important costs or benefits; (ii) inappropriate selection of alternatives for comparison; (iii) problems in making indirect comparisons; (iv) inadequate representation of the effectiveness data; (v) inappropriate extrapolation beyond the period observed in clinical studies; (vi) excessive use of assumptions rather than data; (vii) inadequate characterization of uncertainty; (viii) problems in aggregation of results; (ix) reporting of average cost-effectiveness ratios; (x) lack of consideration of generalizability issues; and (xi) selective reporting of findings. In each case examples are given from the literature and guidance is offered on how to detect flaws in economic evaluations.

Impact of donepezil use in routine clinical practice on health care costs in patients with Alzheimer's disease and related dementias enrolled in a large medicare managed care plan: A case-control study

BACKGROUND

Clinical studies have shown efficacy of cholinesterase inhibitors (eg, donepezil) in mild to moderate Alzheimer's disease (AD). However, there are limited studies examining the impact on health care costs of cholinesterase inhibitors prescribed in routine clinical practice.

OBJECTIVE

The purpose of this study was to estimate the impact of donepezil use on health care costs and utilization in patients with mild to moderate AD and related dementias.

METHODS

This case-control study was conducted using data from the Health Insurance Plan of Greater New York (New York, New York). Data from patients with predominantly mild to moderate AD and related dementias who were enrolled in this Medicare managed care plan from January 1, 1999, to December 31, 2002, were included. The health care costs and utilization of patients who had received donepezil prescribed in routine clinical practice were compared with those of patients who had never received donepezil or other cholinesterase inhibitors (control group). The 2 study groups were matched for age, sex, number of comorbid conditions, and presence of complications of late-stage dementia. Regression analysis was used to estimate the impact of donepezil use on health care costs and utilization during a 12-month follow-up period, controlling for characteristics associated with the outcomes. The analyses did not use a direct measure of disease severity but instead used proxy measures of severity based on medical conditions associated with late-stage dementia.

RESULTS

Data from 687 patients were included in the study. The donepezil group comprised 229 patients (140 women, 89 men; mean age, 79.6 years); the control group, 458 patients (280 women, 178 men; mean age, 80.0 years). The mean costs of medical services per year in the donepezil group were US $2500 (95% CI, $300-$4671) less than those in the control group (P = 0.024). Lower medical costs in the donepezil group ($3325; 95% CI, $1163-$5486; P < 0.003 vs controls) were largely attributable to the lower costs of services performed in the hospital ($2594; 95% CI, $846-$4341; P < 0.004 vs controls) and postacute skilled nursing facility (SNF) ($1012; 95% CI, $444-$1579; P < 0.001 vs controls), which were partially offset by $1241 in higher prescription, physician's office, and outpatient hospital costs. Patients receiving donepezil had shorter mean lengths of stay in the hospital (3.00 vs 5.43 days; 95% CI, 0.66-4.19; P < 0.008) and postacute SNF (0.42 vs 3.40 days; 95% CI, 1.28-4.69; P < 0.001) but a higher mean number of physician's office visits (10.91 vs 7.91 visits; 95% CI, 1.63-4.36; P < 0.001) compared with controls.

CONCLUSIONS

In this case-control study in patients with predominantly mild to moderate AD and related dementias, donepezil therapy prescribed in routine clinical practice was associated with reduced health care costs to the Medicare managed care plan studied. The findings support previous pharmacoeconomic studies with larger sample sizes obtained over a longer period of time, and with improved case-matching criteria.

Economics of dementia and pharmacoeconomics of dementia therapy

BACKGROUND

The economic impact of dementia is not well appreciated, even though Alzheimer's disease and related dementias were the third most expensive health condition in the United States in 2000. In 1997, the cost of managing patients with Alzheimer's disease and other dementias was estimated at US dollar 100 billion. Direct medical costs are compounded by indirect costs of care, including unpaid care and loss of earnings.

OBJECTIVE

The aim of this review was to examine studies of the economic impact of approved treatments for dementia therapy.

METHODS

Searches of the MEDLINE database were conducted to identify prospective, randomized trials and retrospective or modeling studies of the economic impact of dementia medications, as well as analyses of managed care data (years 1996-2004; English language; search terms: dementia or Alzheimer's cross-referenced with economic or costs).

RESULTS

Only 3 studies directly examined the economic effects of dementia therapy. Two of these demonstrated economic benefits of treatment, whereas the third study concluded that there were no benefits; however, the conclusions of the latter study may have been weakened by such factors as the high rate of attrition and biased selection of study participants. Modeling studies and analyses of managed care data also indicate economic benefits from approved treatments.

CONCLUSIONS

Therapies that are efficacious early in the disease can postpone the progression of dementia to more severe stages and may offer economic benefit to patients' families, caregivers, and society.

Evaluation and review of pharmacoeconomic models

Difficult decisions as to whether to provide or withhold drug therapy to patients are needed to be made on a daily basis. These decisions should be based on carefully designed and constructed pharmacoeconomic models, with explicit and justifiable parameter values, validated by publication in peer-reviewed literature. This review describes and evaluates the common types of pharmacoeconomic models, modelling approaches and methods. It also discusses model quality, validity and usefulness.

Modelling the cost effectiveness of cholinesterase inhibitors in the management of mild to moderately severe Alzheimer's disease

OBJECTIVE

To estimate the cost effectiveness (from the UK NHS and personal social services perspective) of the cholinesterase inhibitors donepezil, rivastigmine and galantamine compared with usual care in the treatment of mild to moderately severe Alzheimer's disease. Patients had a mean age of 74 years, a mean disease duration of 1 year and a mean Alzheimer's disease assessment scale-cognitive subscale score of 24.

METHODS

A pharmacoeconomic model was used to predict long-term outcomes over a 5-year time horizon and to estimate the cost effectiveness of cholinesterase inhibitors for the management of Alzheimer's disease. The model structure is informed by a systematic review of the literature on the clinical and cost effectiveness of cholinesterase inhibitors and a review of the literature on the costs and outcomes associated with treatment for Alzheimer's disease. The main outcome measure used was the cost per quality-adjusted life-year (QALY) gained. All healthcare costs (excluding cholinesterase inhibitor costs) were indexed to pounds sterling (2003 values). Drug costs are 2005 values. Multivariate probabilistic sensitivity analysis and scenario analysis were undertaken to assess uncertainty in the results.

RESULTS

The clinical benefits on cognition from treatment with cholinesterase inhibitors resulted in an incremental cost per QALY gained ranging from 53,780 pounds sterling to 74,735 pounds sterling, over 5 years (vs usual care). Uncertainty analysis suggests that the probability of any of these treatments having an incremental cost per QALY of < 30,000 pounds sterling is < 21%. The key determinants of cost effectiveness were the effectiveness of treatment, the mean treatment cost and the cost savings associated with an expected delay in disease progression.

CONCLUSIONS

Results presented in this paper suggest that the use of cholinesterase inhibitors may not be a cost-effective use of NHS resources. Guidance from the National Institute for Health and Clinical Effectiveness (NICE) in the UK on their judgements surrounding the acceptability of technologies as an effective use of resources, indicates there would need to be special reasons for accepting cholinesterase inhibitors as a cost-effective use of NHS resources.

Unfinished symphony: a tribute to the life and career of Bernie O'Brien (1959-2004)

The death of Bernie O'Brien in February 2004 brought a premature end to one of the most productive and influential careers in the area of health technology assessment and economic evaluation. A long-term member of the Society for Medical Decision Making, Bernie will be remembered for his research contributions in areas including outcome valuation, decision modeling, statistical methods in economic evaluation, and applied cost-effectiveness studies. He was also an excellent communicator and teacher and, above all, a fun guy to work with. In this article, the authors provide a review of Bernie's academic contributions.

The economic benefits of acetylcholinesterase inhibitors for patients with Alzheimer disease and associated dementias

Most cost-effectiveness studies using simulation modeling have demonstrated that donepezil, rivastigmine, and galantamine are cost effective for the treatment of mild-to-moderate Alzheimer disease (AD). These conclusions are in large part based on the assumption that improvement in cognitive status, or prevention of cognitive and functional decline, reduces the amount of time patients spend institutionalized or receiving other full-time care. However, as discussed in this article, outcomes besides delay to institutionalization affect the costs of AD. In reviews of utilization data from Medicare and managed care organizations, it was noted that hospitalization and post acute care in skilled nursing facilities accounted for the largest amount of excess direct costs, even among patients with mild or moderate AD. These utilization reviews also suggest that many patients with AD and related dementias require inpatient care because they are not able to self-manage comorbid conditions. The improvements in cognitive status and daily functioning associated with acetylcholinesterase inhibitor (AChEI) therapy are expected to translate into improved management of comorbidities and reduced caregiver burden, thus reducing the total cost of care. To confirm these and other economic benefits of AChEIs, pharmacoeconomic outcomes should be evaluated routinely as part of randomized, controlled trials and through well-controlled observational studies of AD patients in community and institutional settings.

Cost effectiveness of cholinesterase inhibitors in the treatment of Alzheimer's disease: a review with methodological considerations

Cholinesterase inhibitors have been available for the treatment of Alzheimer's disease since 1993. They have significantly positive effects on cognitive functioning and other domains of functional capacity, such as activities of daily life in terms of efficacy, but the clinical value of these effects are under discussion. Cholinesterase inhibitors may also influence behavioural and psychological symptoms in Alzheimer's disease. Cholinesterase inhibitors are also regarded as rather expensive and, therefore, the question of cost effectiveness is essential. Pharmacoeconomic evaluations of cholinesterase inhibitors have so far been conducted in retrospect on efficacy data from prospective randomised clinical trials combined with economic data from other sources. There are no published specific cost-effectiveness studies of cholinesterase inhibitors which prospectively collected empirical data on costs and outcomes. There is only one published randomised clinical trial with such empirical data with a cost consequence analysis design, indicating cost neutrality. Several types of models to describe the long-term effects have been published, indicating cost effectiveness. However, due to methodological considerations, the validity of these models is difficult to judge. A research agenda for the cost effectiveness of cholinesterase inhibitors is proposed, including long-term studies with empirical data on resource use, costs and outcomes, studies on quality of life, informal care and behavioural and psychological symptoms, combination and comparative studies on mild cognitive impairment.

The cost-benefit of cholinesterase inhibitors in mild to moderate dementia: a willingness-to-pay approach

OBJECTIVE

This study aimed to measure the economic value of cholinesterase inhibitors when used to treat Alzheimer's disease using the willingness-to-pay (WTP) approach and the framework of cost-benefit analysis.

METHODS AND STUDY DESIGN

A cost-benefit analysis using the WTP approach was employed. The study sample consisted of 28 nonprofessional caregivers of outpatients with mild to moderate dementia from Toronto, ON, Canada. The caregivers were presented with four scenarios. In the first scenario, scenario A, a hypothetical patient with mild dementia was stabilised with a cholinesterase inhibitor. In the second scenario, scenario A with adverse effects, the above patient (A) experienced adverse effects caused by the drug. In the third scenario, scenario B, the patient exhibited behavioural symptoms in addition to mild dementia, and both were stabilised with the drug. In the fourth scenario, scenario B with adverse effects, the above patient (B) experienced adverse effects caused by the drug. The caregivers were then asked what amount they would pay, in Canadian dollars, each year to buy the medication, assuming that they were the caregivers of the patient described. A multivariate regression analysis was performed to assess the relationship between the demographic data (including the caregiver's yearly income) and the WTP. The average WTP was also predicted for the general population and the elderly population of Canada using data from Statistics Canada, and these values were compared with the cost of the medication.

STUDY PERSPECTIVE

Nonprofessional caregiver perspective. All monetary values are 1999 values unless otherwise specified.

RESULTS

The mean yearly WTP was $Can4540 (95% CI 2334-6746) for scenario A, $Can3686 (95% CI 1530-5842) for scenario A with adverse effects, $Can5003 (95% CI 2661-7345) for scenario B and $Can4486 (95% CI 2222-6750) for scenario B with adverse effects. The WTP decreased when drug adverse effects were present (significantly in scenario A; p = 0.04), but did not significantly increase when behavioural symptoms were present and stabilised. In all scenarios, caregiver yearly income was the only significant predictor of WTP, in the direction expected. For all scenarios, the calculated WTPs from the regression analysis using our sample mean, the average Canadian population data and the elderly population data were all higher than the yearly cost of the cholinesterase inhibitors, with the net benefit ranging from $Can1723 to $Can4508.

CONCLUSIONS

The results of the study, from a small sample of nonprofessional caregivers, revealed that the caregivers are willing to pay more for cholinesterase inhibitors than the drugs cost, even when the adverse effects of the drugs are taken into consideration. This indicates a net benefit for cholinesterase inhibitors in the treatment of mild to moderate dementia from a consumer's point of view.

Cost Effectiveness of Memantine in???Moderately Severe to Severe Alzheimer???s Disease

BACKGROUND

In patients with moderately severe to severe Alzheimer's disease, the N-methyl-D-aspartate (NMDA) antagonist memantine has been shown to improve outcomes and to be associated with reductions in resource utilisation and total healthcare costs relative to no pharmacological intervention after 28 weeks in phase III clinical and pharmacoeconomic studies. However, the longer term cost implications of treatment with memantine are not known.

OBJECTIVE

To evaluate the effect of treatment with memantine in patients with moderately severe to severe Alzheimer's disease on resource use and on cost and patient outcomes in Finland over a 5-year time horizon.

METHODS

A Markov model was constructed to simulate a patient's progression through a finite series of health states with a time horizon of 5 years. The states were defined in terms of physical dependency, place of residency (community or institution), and cognitive function. Each 6-month Markov cycle was repeated ten times. A 5% rate was used to discount costs. Inputs for the model were derived from epidemiological data collected during the Kuopio 75+ Study, a Finnish population-based health survey of dementia and functional capacity among in-dividuals aged >/=75 years. Costs were considered from a societal perspective. Probabilities used in the model, together with cost and resource use differences between treatment with memantine (Ebixa((R)), Namenda((R)), Axura((R))) and no pharmacological intervention, were derived from a randomised, double-blind, placebo-controlled clinical trial that included an economic assessment. This study enrolled 252 patients with moderately severe to severe Alzheimer's disease. We took a conservative approach that assumed that the effectiveness of treatment with memantine was limited to 12 months' duration. Monte Carlo simulations were performed to evaluate the effect of treatment with memantine on duration of independence and time to institutionalisation. Sensitivity analyses included memantine efficacy best- (5 years) and worst- (6 months) case scenarios, and an analysis in which 5% discounting was not applied.

RESULTS

Memantine therapy was associated with approximately 4 extra months of independence, 1 additional month of residence in the community, and a cost reduction relative to placebo of approximately euro1700 per patient over 5 years, despite the limiting of persistence of efficacy to 12 months (year of costing, 2001). Monte Carlo simulations and sensitivity analyses supported the findings.

CONCLUSION

According to the model, over 5 years the additional drug costs of treating patients with moderately severe to severe Alzheimer's disease with memantine were amply offset by cost savings related chiefly to increased independence and delayed institutionalisation.

Análisis de los costes de la enfermedad de Alzheimer en función del deterioro cognitivo y funcional

BACKGROUND AND OBJECTIVE

This study aims to identify the relationship between costs of medical and social attention in patients with dementia of Alzheimer disease (AD) type and clinical and sociodemographic data of patients and their caregivers.

PATIENTS AND METHOD

It was an analytic observational study in a cohort of patients diagnosed with Alzheimer's disease who received ambulatory attention. Information about the use of health-related resources was collected and costs were estimated from a societal perspective. Indirect costs were calculated using a replacement cost approach. Patients and caregivers were examined with the Mini-Mental State Examination (MMSE), the Rapid Disability Rating Scale (RDRS-2), the Neuropsychiatric Inventory (NPI), the Burden Interview (BI) and the Resource Utilization in Dementia (RUD). Patients were grouped taking into account the score obtained in the MMSE.

RESULTS

A cohort of 417 patients, mean age (SD) 75.2 (6.6) years, 71% females, was studied. Disease severity levels were distributed as follows: MMSE, 26% for MMSE > 19, 66% for MMSE = 19-11, and 8% for MMSE < 11. 69% of caregivers were women, with a mean age of 57.1 (15.8) years. The cost per patient and per month was estimated to be 419.3 Euro for MMSE > 19, 641.9 Euro for MMSE = 19-11, and 1150.6 Euro for MMSE < 11.

CONCLUSIONS

The societal cost of AD increases dramatically with increasing disease severity. Caregiver burden and sex as well as the marital status of patients are associated with the cost of the disease.

Stroke, dementia, and drug delivery

Stroke and dementia represent a major health burden for elderly subjects as they are associated with significant morbidity and mortality. The rates of stroke and dementia are progressively increasing due to the ageing population in most westernized countries. Therefore, both these conditions represent a major therapeutic target. However, the therapeutic options available for the management of stroke and dementia remain largely unsatisfactory, the main reason being the difficulty in transferring the results obtained in animal and in vitro studies to the clinical setting. This review focuses on the recent advances in pathophysiology and treatment of these conditions and future directions for research. Moreover, the technique of functional magnetic resonance imaging is discussed in detail as a tool to assess the effects of therapeutic agents on the central nervous system and monitor the progression of diseases. Finally, an overview of the issue of drug delivery into the central nervous system is presented.

Rational choice of cholinesterase inhibitor for the treatment of Alzheimer's disease in Canada: a comparative economic analysis

BACKGROUND

Cholinesterase inhibitors, such as galantamine, donepezil and rivastigmine are approved for symptomatic treatment of Alzheimer's Disease (AD) in Canada. In making choices amongst these drugs, one should consider their clinical merits and their economic implications.

METHODS

Each drug's short-term efficacy was estimated based on independent Cochrane reviews of the clinical trials. Long-term clinical and economic outcomes were estimated using the Assessment of Health Economics in Alzheimer's Disease (AHEAD) model.

RESULTS

While all treatments reduced the need for full-time care, only galantamine and donepezil 10 mg reduced the overall management costs of AD patients. The somewhat greater cognitive effect provided over six months by galantamine leads to the longest estimated delay before full-time care is required and, consequently to lower overall costs, with savings estimated at between 323 dollars and 4,246 dollars.

CONCLUSION

Although there is uncertainty in estimated results, the best information currently available suggests that the first choice for treatment of AD should be galantamine. These results should be interpreted with caution, however, as results are not based on direct comparisons among the drugs and the differences emerging from meta-analyses of the trials are relatively small.

When should functional neuroimaging techniques be used in the diagnosis and management of Alzheimer's dementia? A decision analysis

BACKGROUND

Functional neuroimaging, including positron emission tomography (PET), has been proposed for use in diagnosing Alzheimer's disease-related dementia (AD).

OBJECTIVE

The objective of this study was identify the circumstances under which PET scanning for the diagnosis of AD maximizes health outcomes.

METHODS

A Markov-model-based decision analysis was conducted using estimates derived from the literature on AD epidemiology, the accuracy of PET, and donepezil treatment efficacy. The target population for the analysis was assumed to be US men and women who either have mild AD or are asymptomatic but at an elevated risk of developing AD owing to disease in a first-degree relative (parent or sibling). The time horizon was the patient lifetime. We compared treatment 1) based on an American Academy of Neurology (AAN) clinical evaluation either alone; 2) in combination with PET scanning; or 3) empirically based on a family history. Outcomes measures were life expectancy, quality-adjusted life-years (QALYs), and (severe) dementia-free life expectancy (SDFLE).

RESULTS

For both patient populations, treating all patients based on an AAN evaluation without further testing using PET resulted in the greatest gains in life expectancy, QALYs, and SDFLEs. PET-based testing was the second preferred strategy compared to no intervention. The rankings of the strategies were sensitive to severity of treatment complications: analyses of hypothetical treatments with the potential for severe complications indicated that testing was preferred if the treatment was effective but had moderate complications.

CONCLUSIONS

These results suggest that current treatments, which are relatively benign and may slow progression of disease, should be offered to patients who are identified as having AD based solely on an AAN clinical evaluation. A clinical evaluation that includes functional neuroimaging based testing will be warranted, however, when new treatments that are effective at slowing disease progression but have the potential for moderate to severe complications become available.

Cost-effectiveness of PET in the diagnosis of Alzheimer disease

PURPOSE

To evaluate the cost-effectiveness of positron emission tomography (PET) in the diagnosis of Alzheimer disease (AD) in community-dwelling patients with mild or moderate dementia who present to specialized AD centers.

MATERIALS AND METHODS

A decision-analytic model was used to compare costs and quality-adjusted life years (QALYs) associated with strategies involving single photon emission computed tomography (SPECT), dynamic susceptibility-weighted contrast material-enhanced magnetic resonance (MR) imaging, and PET as functional imaging adjuncts to the standard clinical work-up. Sensitivity analyses were performed to examine changes in test characteristics, health-related quality-of-life survey instruments, therapeutic effectiveness, and treatment rules.

RESULTS

The use of PET to confirm the results of the standard clinical work-up cost more but yielded fewer benefits than a strategy in which dynamic susceptibility-weighted contrast-enhanced MR imaging was substituted for the typically performed structural computed tomography. This relationship remained stable in scenarios in which standard diagnostic work-up accuracy, drug treatment effectiveness, and version of the Health Utilities Index were altered. Dynamic susceptibility-weighted contrast-enhanced MR imaging cost US dollars 598800 per QALY gained (range, US dollars 74400 to US dollars 1.9 million per QALY), compared with the cost of the standard diagnostic work-up. Treating all patients with dementia was the dominant imaging strategy, except when side effects in patients with non-AD-related dementia were modeled. In all scenarios, SPECT yielded fewer benefits than other strategies at a higher cost.

CONCLUSION

PET may have high diagnostic accuracy, but adding it to the standard diagnostic regimen at AD clinics would yield limited, if any, benefits at very high costs.

Economic evaluation of galantamine in the treatment of mild to moderate Alzheimer's disease in the United States

BACKGROUND

Alzheimer's disease (AD) is estimated to affect up to 11% of those aged > or =65 years in the United States, and the number of patients with AD is predicted to increase over the next few decades as the population ages. The substantial social and economic burden associated with AD is well established, with the cost of management increasing as the disease progresses.

OBJECTIVE

The aim of this study was to evaluate the economic impact of galantamine 16 and 24 mg/d relative to no pharmacologic treatment in the management of mild to moderate AD in the United States based on the concept of need for full-time care (FTC).

METHODS

Calculations were made using the Assessment of Health Economics in Alzheimer's Disease model, which applies predictive equations to estimate the need for FTC and the associated costs. The predictive equations were developed from longitudinal data on patients with AD. Inputs to the equations were derived by analyzing the data from 2 randomized, placebo-controlled, galantamine clinical trials. Resource use (from a payer perspective) was estimated from US clinical trial data, and costs were estimated from several US databases. Analyses were carried out over 10 years, and costs and benefits were discounted at 3%.

RESULTS

In the base case, 3.9 to 4.6 patients need to start treatment with galantamine to avoid 1 year of FTC, depending on dose. Treated patients spent 7% to 8% more time pre-FTC and 12% to 14% less time requiring FTC, resulting in savings of 2408 to 3601 US dollars. Time horizons below 3 years, very high discontinuation rates, or increased survival with galantamine reversed the savings. Conversely, limiting treatment to responders delayed FTC by 6 to 7 months, with savings of approximately 9097 to 11,578 US dollars.

CONCLUSIONS

These results suggest that use of galantamine in patients with AD in the United States could reduce the use of costly resources such as formal home care and nursing homes, leading to cost savings over time.

Pharmacoeconomics of mild cognitive impairment

There is little written about the pharmacoeconomics of mild cognitive impairment (MCI), particularly with regard to intervention. The aim of the paper is to highlight methodological issues and to present some results that are of importance when drug interventions of MCI are discussed. There is a relationship between severity of dementia and costs, but to what extent such results can be extrapolated to MCI is not known. Even if it is logical to consider a postponement of the shift from MCI to dementia as cost effective, this statement must be proven, particularly in light of the insufficient knowledge about the effects of anti-dementia drugs on survival. From the Kungsholmen project in Sweden, there are indications that the postponement between MCI and manifest dementia may result in short-term benefits (a few years) of about SEK50,000 (5300 US dollars).

Cost of illness of Alzheimer's disease: how useful are current estimates?

PURPOSE

The goal of this literature review was to determine the validity and policy relevance of recent estimates from many countries of Alzheimer's disease (AD) costs.

DESIGN AND METHODS

We searched Medline and other databases for English-language peer-reviewed journals on total, direct, indirect, and per case cost of AD that used 1985-2000 data. We adjusted costs of U.S. studies for inflation. We adjusted non-U.S. studies by that country's medical cost inflation rate and purchasing power parity (PPP).

RESULTS

Of 71 studies identified, 21 met all criteria for inclusion. Annual inflation adjusted U.S. total costs of AD varied from $5.6 billion to $88.3 billion. AD total per case (direct and indirect) costs varied from $1,500 to $91,000; indirect/family costs varied from $3,700 to $21,000. Among non-U.S. studies, AD annual adjusted per case costs varied from PPP $2,300 to PPP $30,000. Cost variation was due to diverse study methods, data sources, services included, and lack of clear differentiation between cost of AD and cost of caring for people with AD.

IMPLICATIONS

The cost of AD is high, although reliable estimates are not available. Costs are likely to rise given expected demographic shifts in all countries. The widely variable cost estimates call into question the real costs of Alzheimer's disease and their applicability to policy initiatives.

Pharmacoeconomics of cholinesterase inhibitors in the treatment of Alzheimer's disease

Cholinesterase inhibitors constitute one of few treatment options available for Alzheimer's disease, the most common cause of dementia. The modest effects and relatively high acquisition costs of these drugs make the health economics of dementia an important subject of study. Simulation models can be used to bring together existing data and make predictions of the long-term cost effectiveness of treatment. Most models have been built around cognitive function as a key parameter based on the observed relationship between cognitive function and costs of care. Patients with more severe disease attain higher total costs of care. Also, these patients have a higher share of formal care costs than do patients with mild disease, who are usually looked after by informal caregivers. The valuation of unpaid care is controversial, and the choice of method may affect results considerably. Another important issue is the measurement of health-related QOL in patients with Alzheimer's disease. The few existing studies have used proxy respondents to elicit utility weights in different disease states; however, this methodology has not been validated. It is likely that the increased drug costs incurred by the use of cholinesterase inhibitors will be offset (at least partly) by savings in other healthcare costs. However, these results should be viewed as preliminary, since we are still awaiting data from long-term follow-up studies. Also, the value of treatment for patients and caregivers in terms of QOL improvements has yet to be established.