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

Measuring Value: Cost-Effectiveness Analysis for Occupational Therapy

Stroke rehabilitation is expensive, and recent changes to Medicare reimbursement demand more efficient interventions. The use of cost-effectiveness analysis (CEA) can help occupational therapy practitioners, rehabilitation directors, and payers better understand the value of occupational therapy and decide whether or not to implement new treatments. The objective of this article is to illustrate the contribution of CEA to stroke rehabilitation using a hypothetical new intervention as an example. What This Article Adds: This article facilitates an understanding of the importance of CEA to occupational therapy. It also explains how CEA improves consistency with reporting standards for cost-effectiveness studies.

Validation of a self-administered computerized system to detect cognitive impairment in older adults

There is increasing interest in the development of economical and accurate approaches to identifying persons in the community who have mild, undetected cognitive impairments. Computerized assessment systems have been suggested as a viable approach to identifying these persons. The validity of a computerized assessment system for identification of memory and executive deficits in older individuals was evaluated in the current study. Volunteers (N = 235) completed a 3-hr battery of neuropsychological tests and a computerized cognitive assessment system. Participants were classified as impaired (n = 78) or unimpaired (n = 157) on the basis of the Mini Mental State Exam, Wechsler Memory Scale-III and the Trail Making Test (TMT), Part B. All six variables (three memory variables and three executive variables) derived from the computerized assessment differed significantly between groups in the expected direction. There was also evidence of temporal stability and concurrent validity. Application of computerized assessment systems for clinical practice and for identification of research participants is discussed in this article.

The estimation of utility weights in cost-utility analysis for mental disorders: a systematic review

OBJECTIVE

To systematically review approaches and instruments used to derive utility weights in cost-utility analyses (CUAs) within the field of mental disorders and to identify factors that may have influenced the choice of the approach.

METHODS

We searched the databases DARE (Database of Abstracts of Reviews of Effects), NHS EED (National Health Service Economic Evaluation Database), HTA (Health Technology Assessment), and PubMed for CUAs. Studies were included if they were full economic evaluations and reported quality-adjusted life-years as the health outcome. Study characteristics and instruments used to estimate utility weights were described and a logistic regression analysis was conducted to identify factors associated with the choice of either the direct (e.g. standard gamble) or the preference-based measure (PBM) approach (e.g. EQ-5D).

RESULTS

We identified 227 CUAs with a maximum in 2009, 2010, and 2012. Most CUAs were conducted in depression, dementia, or psychosis, and came from the US or the UK, with the EQ-5D being the most frequently used instrument. The application of the direct approach was significantly associated with depression, psychosis, and model-based studies. The PBM approach was more likely to be used in recent studies, dementia, Europe, and empirical studies. Utility weights used in model-based studies were derived from only a small number of studies.

LIMITATIONS

We only searched four databases and did not evaluate the quality of the included studies.

CONCLUSIONS

Direct instruments and PBMs are used to elicit utility weights in CUAs with different frequencies regarding study type, mental disorder, and country.

Economic evaluation of the impact of memantine on time to nursing home admission in the treatment of Alzheimer disease

OBJECTIVE

An observational study showed that combining memantine with a cholinesterase inhibitor (ChEI) treatment significantly delayed admission to nursing homes in patients with Alzheimer disease (AD). Our study aimed to evaluate the economic impact of the concomitant use of memantine and a ChEI, compared with a ChEI alone, in a Canadian population of patients with AD.

METHOD

A cost-utility analysis using a Markov model during a 7-year time horizon was performed according to a societal and Canadian health care system perspective. The Markov model includes the following states: noninstitutionalized, institutionalized, and deceased. The model includes transition probabilities for institutionalization and death, adjusted with mortality rates specific to AD. Utilities associated with institutionalization and noninstitutionalization were included. For the health care system perspective, costs of medication as well as costs of care provided in the community and in nursing homes were considered. For the societal perspective, costs of direct care and supervision provided by caregivers were added.

RESULTS

From both perspectives, the concomitant use of a ChEI and memantine is a dominant strategy, compared with the use of a ChEI alone. On a per patient basis, there was a gain of 0.26 quality-adjusted life years with the treatment including memantine and cost decreases of Can$21 391 and Can$30 512, respectively, for the societal and health care system perspective.

CONCLUSIONS

This economic evaluation indicates that institutionalization is the largest cost component in AD management and that the use of memantine, combined with a ChEI, to treat AD is a cost-effective alternative, compared with the use of a ChEI alone.

Persistence with cholinesterase inhibitor therapy in a population-based cohort of patients with Alzheimer's disease

PURPOSE

To estimate the risk (and determinants) of discontinuing cholinesterase inhibitors (ChEIs) in a population-based sample of Alzheimer's disease (AD) patients.

METHODS

This is a retrospective cohort study based on linked de-identified administrative health data from the province of Saskatchewan, Canada. The cohort included all AD patients receiving a ChEI prescription during the first year of provincial coverage (2000-2001). Persistence was defined as no gap of 60+ days between depletion and subsequent refill of a ChEI prescription. Kaplan-Meier analysis was used to estimate the risk of discontinuation over 40 months. Cox regression with time-varying covariates was used to assess risk factors for ChEI discontinuation.

RESULTS

The sample included 1080 patients (64% female, average age 80 +/- 7 years). Baseline mean (SD) Mini-Mental State Examination (MMSE) and Functional Activities Questionnaire (FAQ) scores were 20.8 (4.4) and 17.5 (7.7), respectively. Over 40 months, 84% discontinued therapy. The 1-year risk of discontinuation was 66.4% (95%CI 63.5-69.3%). Discontinuation was significantly more likely for females (adjusted HR 1.34, 95%CI 1.16-1.55) and among those with lower MMSE scores (2.52, 2.01-3.17 if <15), not receiving social assistance (1.25, 1.07-1.45), and paying at least 65% of total prescription costs (1.51, 1.30-1.74). It was significantly less likely for patients with frequent physician visits (0.78, 0.66-0.93, for 7-19 vs. <7 visits), higher Chronic Disease Scores (0.74, 0.61-0.89, for 7+ vs. <4), and FAQ scores of 9+ (0.82, 0.69-0.99).

CONCLUSION

The likelihood of discontinuing ChEI therapy was high in this real-world sample of AD patients. Significant predictors included clinical, socioeconomic, and practice factors.

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.

Predictors of adherence among Alzheimer's disease patients receiving oral therapy

OBJECTIVES

Treatment effectiveness depends upon administering medications as prescribed, and adherence is critical for Alzheimer's disease (AD) patients to receive optimal benefit from therapy. The objective of this study was to investigate factors associated with adherence to AD oral medications.

METHODS

This retrospective claims analysis identified AD patients who initiated oral AD therapy (rivastigmine, donepezil, galantamine, or memantine) between January 1, 2006 and December 31, 2007 from a large US health plan. Patient baseline characteristics were assessed during the 6-month pre-index period; outcomes were assessed during the 1-year post-index period. Pill burden was measured as a count of unique units of medication/day. Adherence was measured by medication possession ratio (MPR), with MPR >or=80% defined as adherent. Multivariate logistic regression was used to assess how potential covariates affect adherence probability.

RESULTS

A total of 3091 AD patients (36% male; mean age 80 [8.25 SD]) were identified. Only 58% of patients were adherent to oral AD medications. Compared to patients <75 years, patients >or=86 years were likely to be more adherent (OR = 1.401, p < 0.001). Other factors found to be positively associated with the probability of adherence to AD medications were male gender (OR = 1.175, p < 0.05), overall pill burden (OR = 1.192, p < 0.001), and a lower formulary tier status of the AD medication (OR = 1.332, p < 0.001).

CONCLUSION

Among the several variables assessed, being male, >or=86 years of age, having a greater overall daily pill burden, or using a lower formulary tier AD medication was associated with better adherence to oral AD medication in patients diagnosed with AD. The database had no information on caregiver support, medication management interventions, or use of adherence aids that may have affected adherence in this cohort, yet, a substantial proportion of patients (42%) remained non-adherent. A better understanding of the causes of non-adherence is necessary, and methods to improve adherence, such as transdermal medications and educational programs, should be considered.

Willingness-to-pay for reductions in care need: estimating the value of informal care in Alzheimer's disease

OBJECTIVE

To estimate the value of informal care in Alzheimer's disease using contingent valuation.

METHODS

A questionnaire was administered to 517 primary carers in four countries (UK, Spain, Sweden, and US). Dichotomous choice and bidding game methods were used to elicit their willingness to pay for a reduction in care burden by 1 h per day, or a total elimination of care needs. Further, the relationship between carer willingness to pay and carer and patient characteristics including disease severity and income was examined.

RESULTS

Carers spend on average about 7-9 h per day on giving care to their patient, of which 4-5 h constituted basic and instrumental ADL tasks. For a 1 h reduction in need for care per day, carers in the UK, Spain, Sweden, and US said that they were willing to pay pound105, pound121, pound59, and pound144 per month respectively. The willingness to pay was higher for carers with higher disposable income while the influence of other determinants varied across countries. About one-third of carers were not willing to pay anything for a reduction in care.

CONCLUSIONS

Carers' stated willingness to pay for reductions in care giving time is substantial and comparable to the prices currently paid for treatments that achieve this benefit. Its determinants seem more directly related to carer status than directly to patient status and may vary by region and by cultural and sociologic factors.

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.

The cost of dementia in Europe: a review of the evidence, and methodological considerations

Alzheimer's disease (AD) is a leading cause of disability in the elderly, leading to a high burden on caregivers and costs to society. This article describes the current level of data availability regarding the costs of AD in Europe, summarizes and compares findings from previous studies in different countries, and discusses the applicability of available data for modelling purposes. A literature review was conducted for papers in any language reporting data on costs of care for patients with diagnosed dementia or possible/probable AD. Only papers reporting patient-level data on costs were included. A total of 16 studies were identified: from the Nordic region (4), the UK (3), Spain (3), France (2), Italy (2), Belgium (1) and Germany (1). There is large variation in total cost estimates, depending on, for example, differences in study methodology, setting, type and severity of patients included, range of costs assessed and the choice of principle for valuing informal care. The median value for total annual care costs in all studies was Euro28 000 (range Euro6614-Euro64 426) [year 2005 values]. Few studies assessed aspects of disease severity other than cognitive function. The costs of AD in Europe are substantial and increase with disease severity. Methodological differences between studies make comparison across countries and healthcare systems difficult, and there is a need to standardize methods for assessing and valuing informal care. Patient-level information on resource use is required to analyse determinants of care costs and predict the impact of therapeutic interventions. More data are needed to support future economic evaluations of therapies for AD.

Sociodemographic and clinical correlates of utility scores in Alzheimer's disease

OBJECTIVES

To examine the relationship between psychiatric symptoms, cognitive performance, functional capacity and quality of life in Alzheimer's disease (AD), and change in the Health Utilities Index (HUI)-Mark III, a widely used generic, multiattribute preference-based health-status classification system.

METHODS

Follow-up data were obtained from caregiver proxy raters at 3, to 6, and 9-months postrandom assignment concerning 421 patients with AD, living with at least one caregiver in a noninstitutional setting, who participated in the Clinical Antipsychotic Trial of Intervention Effectiveness-AD of antipsychotic medication. Spearman rank correlations, multivariate linear regression, and mixed modeling were used to examine the correlates of change in the HUI.

RESULTS

HUI scores decreased by an average of -0.061 over 9 months. Analysis revealed weak bivariate, and largely, nonsignificant multivariate relationships between change in HUI scores and sociodemographic characteristics, psychiatric symptoms, and cognitive performance. There were highly significant associations between decreases in health utilities and change in the AD Cooperative Study for Activities of Daily Living scale (ADCS-ADL) and AD-Related Quality of Life (ADRQoL) (both P < 0.001), even after controlling for other factors. Adjusted R(2) values ranged from 0.14 to 0.20.

CONCLUSION

In AD patients requiring antipsychotic treatment, only weak relationships were found between changes in the HUI and sociodemographic and clinical indicators. While functional capability and quality of life showed more significant associations, less than 20% of the variance in health utility could be explained. Significant cognitive impairment and the need to rely on proxy raters may limit the usefulness of utility measurement in AD patients with serious behavioral symptoms.

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.

Improving drug trials for mild to moderate Alzheimer's disease

Over the last two decades, numerous studies have been conducted on subjects with mild to moderate Alzheimer's disease. The objective of this paper was to review concerns raised in the literature about the design and methodology of these clinical trials and to make recommendations to deal with the limitations identified. Concerns raised in the literature include the following: undue focus on statistical rather than clinical significance; the need for further pharmacoeconomic evaluations; the nonrepresentativeness of the study populations; perceived inadequacies in the direct-comparison studies conducted to date; the limitations of open-label extension studies; the inability of standard psychometric tools to document all the relevant treatment effects; the ethics of placebo-controlled trials; and, problems caused by the actions of the regulatory authorities. Recommendations are made to deal with the issues raised.

Economic evaluation of rivastigmine in patients with Parkinson's disease dementia

BACKGROUND

The positive results of a randomised clinical trial of rivastigmine in patients with dementia associated with Parkinson's disease have been published recently. Patient-level healthcare utilisation data were also collected, and this report is the economic evaluation based on these data.

OBJECTIVE

To determine the cost effectiveness of rivastigmine 3-12 mg/day in patients in whom mild to moderate dementia developed at least 2 years after they received a clinical diagnosis of Parkinson's disease.

METHODS

A cost-effectiveness analysis was performed by applying Canadian and UK cost weights (year 2004 values) to healthcare utilisation data collected prospectively during a randomised, double-blind, multinational, 24-week trial of rivastigmine 3-12 mg/day (n = 362) versus placebo (n = 179). Patients were > or =50 years of age, had a Mini-Mental State Examination (MMSE) score of between 20 and 24 and had contact with a responsible caregiver at least 3 days a week.Quality-adjusted survival time, transformed from MMSE scores, was the measure of effectiveness. Caregiver costs included paid and unpaid time, and direct costs included concomitant medications, outpatient care, hospitalisations, long-term care and study medications. Analysis was conducted from a societal perspective with a time horizon of 24 weeks.

RESULTS

Consistent with the improvement in clinical outcomes, there was an observed increase in quality-adjusted survival time in the rivastigmine arm of 2.81 quality-adjusted life-days (two-sided p-value 0.13 [90% CI -0.243, 5.86]). Using Canadian price weights, there was an observed increase in cost in the rivastigmine arm of Can 55.76 dollars(two-sided p-value 0.98 [90% CI -3431, 3543]), with a resulting incremental cost-effectiveness ratio of Can 7429 dollars per QALY. Using UK price weights, there was an observed decrease in cost in the rivastigmine arm of pound 26.18 (two-sided p-value 0.99 [90% CI -2407, 2355]).

CONCLUSION

Although no between-treatment differences in cost were seen, the small sample size, highly variable cost distributions and short time horizon prevent us from making strong conclusions with regard to the effect of rivastigmine on total costs and, by inference, on cost effectiveness.

Galantamine prolonged-release formulation in the treatment of mild to moderate Alzheimer's disease

The primary objective of this study was to evaluate the efficacy and tolerability of a flexible dosing regimen (16 or 24 mg/day) of galantamine prolonged-release capsule (PRC) compared with placebo in subjects with mild to moderate Alzheimer's disease (AD). This phase III, double-blind, placebo- and active-controlled, parallel-group trial randomized 971 patients to treatment for 6 months. Efficacy endpoints included change in the 11-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog/11), Clinician's Interview-Based Impression of Change plus caregiver input (CIBIC-plus), Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL), and Neuropsychiatric Inventory (NPI) scores. Galantamine was associated with significant improvements in the ADAS-cog/11 score but not in the CIBIC-plus or NPI scores. Galantamine PRC was associated with significant improvement in ADCS-ADL scores. Galantamine PRC had similar tolerability and safety profiles compared with twice-daily galantamine, and when administered as a once-daily flexible dosing regimen of 16 or 24 mg/day, was demonstrated to be as safe and effective for the treatment of mild to moderate AD.

The Use of the Occupational Disruptiveness Scale of the Neuropsychiatric Inventory-Nursing Home Version to Measure the Impact of Rivastigmine on the Disruptive Behavior of Nursing Home Residents With Alzheimer’s Disease

OBJECTIVES

The Neuropsychiatric Inventory-Nursing Home Version (NPI-NH) was used to study the impact of rivastigmine (Exelon; Novartis Pharmaceuticals Corporation, East Hanover, NJ), on occupational disruptiveness (OD), a proxy measure for professional caregiver burden.

METHODS

The study was a prospective, multicenter, open-label, single-arm trial with NH residents prescribed rivastigmine (up to 6 mg bid) for Alzheimer's disease (AD) treatment. The NPI-NH was completed by NH staff caregivers at time of initiation of treatment with rivastigmine (T1), at treatment weeks 10 to 14 (T2), at treatment weeks 24 to 28 (T3), and at treatment weeks 50 to 54 (T4).

RESULTS

Observations ranged from 173 at baseline to 73 at week 52. All but one patient had either moderate or severe dementia. Total OD score means were 4.7 +/- 6.1, 3.9 +/- 5.0, 4.19 +/- 5.6, and 2.79 +/- 2.8 at baseline, and weeks 12, 26, and 52 (T1-T4), respectively, with significant difference found between T1 and T4. Except for euphoria and disinhibition at T3 and T4, all correlations between OD scores and the domain scores of the NPI, were significant. Rivastigmine dose was an independent variable that affected OD change.

CONCLUSION

Treatment with rivastigmine was associated with a reduction in the self-reported professional caregiver burden, as assessed by the NPI-NH OD scale.

Cost-effectiveness of memantine for moderate to severe Alzheimer's disease in Sweden

BACKGROUND

Alzheimer's disease entails enormous costs for society and impairs quality of life for patients and caregivers.

OBJECTIVE

This study estimated the cost-effectiveness of memantine in the treatment of patients with moderately severe to severe cognitive impairment from Alzheimer's disease in Sweden.

METHODS

The study was based on published data from several sources, including a randomized controlled trial of memantine versus placebo and a longitudinal observational study of Alzheimer's disease patients in Sweden. Costs were estimated from the public payer's perspective, including direct costs but excluding costs of informal care, and resource utilization data were taken from the observational study. Cost-effectiveness was quantified as quality-adjusted life-years (QALYs) gained from treatment with the use of previously published utility weights. A Markov simulation model was constructed, incorporating the effect of treatment on cognitive function, physical dependence related to activities of daily living, and institutionalization. Costs and effects for treated and untreated patients were estimated for 5 years (10 cycles). In the base-case analysis, treatment costs were added for 2 years, but the effect on transition probabilities was applied only for the first year of treatment.

RESULTS

Compared with no treatment, memantine treatment was predicted to be associated with lower costs of care, longer time to dependence and institutionalization, and gains in QALYs. Treatment was estimated to decrease formal care costs by 123,600 Swedish kronor (SEK) and, after taking into account the cost of memantine, to lead to net cost savings of 100,528 SEK per patient. Treated patients gained 0.148 QALY over the 5-year simulation.

CONCLUSIONS

From a public payer's perspective, the observed effect of memantine on cognitive and physical function is predicted to translate into economic benefits that offset the added treatment cost. Treatment is also predicted to delay institutionalization, improve independence, and increase QALYs.

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.