Cost-effectiveness analysis of dopamine agonists in the treatment of Parkinson's disease in Japan

Cost-effectiveness of the add-on exenatide to conventional treatment in patients with Parkinson’s disease when considering the coexisting effects of diabetes mellitus

Objective

This study aims to investigate the cost-effectiveness of the add-on exenatide to conventional pharmacotherapy in patients with Parkinson’s disease (PD) when considering the coexistence of diabetes mellitus (DM).

Methods

We used the Keelung and Community-based Integrated Screening databases to understand the medical utilisation in the Hoehn and Yahr stages of patients with PD. A Markov model with 1-year cycle length and 50-year time horizon was used to assess the cost-effectiveness of add-on exenatide to conventional pharmacotherapy compared to conventional pharmacotherapy alone. All costs were adjusted to the value of the new Taiwanese dollar (NT$) as of the year 2020. One-way sensitivity and probability analyses were performed to test the robustness of the results.

Results

From a societal perspective, the add-on exenatide brought an average of 0.39 quality-adjusted life years (QALYs) gained, and a cost increment of NT$104,744 per person in a 50-year horizon compared to conventional pharmacotherapy. The incremental cost-effectiveness ratio (ICER) was NT$268,333 per QALY gained. As the ICER was less than the gross domestic product per capita (NT$839,558), the add-on exenatide was considered to be very cost-effective in the two models, according to the World Health Organization recommendation. Add-on exenatide had a 96.9% probability of being cost-effective in patients with PD, and a 100% probability of being cost-effective in patients with PD and DM.

Conclusion

Add-on exenatide is cost-effective in PD combined with DM. Considering that DM may be a risk factor for neurodegenerative diseases, exenatide provides both clinical benefits and cost-effectiveness when considering both PD and DM.

A review of adverse events linked to dopamine agonists in the treatment of Parkinson's disease

INTRODUCTION

Dopamine agonists are highly effective as adjunctive therapy to levodopa in advanced Parkinson's disease. These drugs have rapidly gained popularity as a monotherapy in the early stages of Parkinson's disease for patients less than 65-70 years old since they are about as effective as levodopa but patients demonstrate a lower tendency to develop motor complications. However, dopamine agonists could have peripheral and central side-effects which are often the reason for the discontinuation of the treatment.

AREAS COVERED

This article presents an overview of the efficacy and the potential negative effects related to the use of dopamine agonists in the treatment of Parkinson's disease.

EXPERT OPINION

Beyond the new generation non ergot dopamine agonists, no strong evidences allow the choice of a specific dopamine agonists for Parkinson 's disease treatment and by now dopamine agonists treatment should be tailored on specific adverse events profile.

The cost-effectiveness of deep brain stimulation in combination with best medical therapy, versus best medical therapy alone, in advanced Parkinson's disease

Parkinson’s disease (PD) is a complex progressive movement disorder leading to motor and non-motor symptoms that become increasingly debilitating as the disease advances, considerably reducing quality of life. Advanced treatment options include deep brain stimulation (DBS). While clinical effectiveness of DBS has been demonstrated in a number of randomised controlled trials (RCT), evidence on cost-effectiveness is limited. The cost-effectiveness of DBS combined with BMT, versus BMT alone, was evaluated from a UK payer perspective. Individual patient-level data on the effect of DBS on PD symptom progression from a large 6-month RCT were used to develop a Markov model representing clinical progression and capture treatment effect and costs. A 5-year time horizon was used, and an incremental cost-effectiveness ratio (ICER) was calculated in terms of cost per quality-adjusted life-years (QALY) and uncertainty assessed in deterministic sensitivity analyses. Total discounted costs in the DBS and BMT groups over 5 years were £68,970 and £48,243, respectively, with QALYs of 2.21 and 1.21, giving an incremental cost-effectiveness ratio of £20,678 per QALY gained. Utility weights in each health state and costs of on-going medication appear to be the key drivers of uncertainty in the model. The results suggest that DBS is a cost-effective intervention in patients with advanced PD who are eligible for surgery, providing good value for money to health care payers.

Pharmacoeconomic considerations of treating patients with advanced Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. In the later (advanced) stages of PD, the initial treatment of early PD becomes less effective and long-term side effects of dopaminergic treatment become apparent. In advanced PD, motor and non-motor complications occur, which increase treatment costs. Increasing disability and impaired activities of daily living concomitantly raise indirect costs, due to loss in productivity. Hence, the economic burden of advanced PD is substantial for both the society and the patients with their caregivers.

AREAS COVERED

A systematic literature search was performed involving the databases NHS CRD (National Health Service Centre for Reviews and Dissemination) and PubMed until July 15, 2011. "Parkinson" [Mesh] and "cost" were used as search terms in PubMed and only "Parkinson" in the CRD database.

EXPERT OPINION

Economic evaluations are scarce and heterogeneous, and their interpretation may be limited due to methodological shortcomings. Dopamine agonists, COMT and MAO-B inhibitors as well levodopa infusion and deep brain stimulation are reported to be cost-effective in the respective decision frameworks. However, these results are heavily dependent on assumptions of drug costs and effect sizes used in the models. More detailed real-life information from long-term clinical trials is needed to feed the economic models, especially for head-to-head comparisons. To date, no economic evaluation has been undertaken for possible neuroprotective/disease modifying effects, and further research is needed for evaluations of interventions for non-motor symptoms.

The use of decision-analytic models in Parkinson's disease: a systematic review and critical appraisal

The aims of this review were to review decision-analytic models used to evaluate interventions in idiopathic Parkinson's disease (PD), and to consider the future directions for development of methods to model the progression of PD over time. A systematic search of the healthcare literature up to June 2010 identified model-based economic evaluations in PD. The modelling methods used in the identified studies were appraised using good practice guidelines for decision-analytic modelling. The review identified 18 model-based evaluations of interventions in PD. All models evaluated treatments targeted towards the motor symptoms of PD or the motor complications of PD treatment. There were no models identified that evaluated interventions targeted towards the non-motor symptoms of PD, such as neuropsychiatric problems or autonomic dysfunction. Consequently, models characterized disease progression in PD using clinical measures of motor functioning. Most studies (n = 13) evaluated medications, three evaluated diagnostic technologies and two examined surgical procedures. Overall, the models reported structural components and data inputs appropriately and clearly, although limited evidence was provided to support choices made on the structures used in the models or the data synthesis reported. Models did not adequately consider structural uncertainty or internal/external consistency. Modelling methods used to date do not capture the full impact of PD. The emphasis in the current literature is on the motor symptoms of PD, characterizing the clinical nature of disease progression, largely neglecting the important impacts of non-motor symptoms. Modelling methods reported for the motor symptoms of PD may not be suitable for future interventions targeted towards modifying disease progression in PD across the entire spectrum of PD. More comprehensive models of disease progression, including both motor and non-motor symptoms will be needed where it is important to capture the effects of interventions more broadly.

Cost effectiveness of pharmacotherapies in early Parkinson's disease

Parkinson's disease is one of the most common chronic neurodegenerative diseases. The progression of disease and the psychosocial consequences exert a major impact on patients' health-related quality of life. Although levodopa provides the best symptomatic benefit with the fewest short-term adverse effects, long-term treatment results in motor complications that are associated with both higher costs and considerable increase in patients' discomfort. The introduction of dopamine agonists early in the treatment of Parkinson's disease leads to a delay of these motor complications, but the treatment is associated with higher costs.In this review we evaluate available cost-effectiveness analyses of the dopamine agonists pramipexole, pergolide, bromocriptine, ropinirole, cabergoline and levodopa in the treatment of early Parkinson's disease. Considerable methodological differences in the identified studies complicate a comparison and impede clear evidence as to which dopamine agonist treatment is the most cost effective in early Parkinson's disease. Novel head-to-head comparisons considering the actual treatment guidelines are necessary to identify the most cost-effective alternative in treating de novo Parkinson's disease patients.

The safety of dopamine agonists in the treatment of Parkinson's disease

Dopamine agonists are highly effective as adjunctive therapy to levodopa in advanced Parkinson's disease. These drugs have rapidly gained popularity as a monotherapy in the early stages of Parkinson's disease for patients < 65-70 years old, because they are about as effective as levodopa, but patients demonstrate a lower tendency to develop motor complications. However, dopamine agonists could have peripheral and central side effects, which are often the reason for the discontinuation of the treatment. This review focuses on the potential negative effects related to the use of dopamine agonists in the treatment of Parkinson's disease.

A Review of the Health-Related Quality of Life and Economic Impact of Parkinson??s Disease

Parkinson's disease (PD) is a chronic, neurodegenerative disease that places a substantial burden on patients, their families and carers, as well as on society as a whole. PD can severely affect the health-related quality of life (HR-QOL) of both patients and their carers and, as the disease progresses, HR-QOL deteriorates. This review aims to critically evaluate the literature on a number of important aspects that influence HR-QOL in relation to PD. Factors associated with a negative impact and ways to improve HR-QOL are highlighted, and tools for HR-QOL assessment reviewed. The economic impact of PD and related cost-effectiveness studies are also reviewed. Over the course of the disease, patients with PD experience changes in their HR-QOL that are affected by factors such as depression, motor complications, education and surgery. However, a lack of uniformity in the choice of HR-QOL tools used in studies makes comparison of results difficult. Research on motor fluctuations and dyskinesias has shown conflicting results, whereas it is clear from the available data that depression needs to be more clearly recognised and treated. Inequality in the numbers of men and women receiving surgery still needs to be addressed and, again, in this area there is a lack of uniformity with respect to assessment for surgery. Education programmes have been shown to be successful in improving HR-QOL, although more research is needed about how to introduce such programmes to all PD patients. In particular, there has been little detailed research into young-onset PD and juvenile patients to assess the true impact of the disease on their HR-QOL. The literature has also shown that PD can affect the HR-QOL of the carer, which may have a 'knock-on' effect for the patient. The HR-QOL of carers needs more attention because these individuals can significantly reduce the burden that would otherwise fall on the health services in terms of cost and care. Research shows that the economic costs of PD are high, particularly for patients in advanced stages of the disease and those with motor complications. Although carer burden is a major source of costs, this is not factored into cost-effectiveness analyses. Furthermore, because too few studies use quality-adjusted life years as their health outcome, particularly in studies of the costs of surgery, comparison of costs of treatments is difficult. The review highlights the need for HR-QOL tools such as the EuroQol-5D to be used together with disease-specific tools to provide the most comprehensive picture of the costs and impact of PD.A recent upsurge in published literature on PD resulting from increased interest in HR-QOL issues has led to an at times overwhelming amount of new information. The present review assembles the most important points relating to HR-QOL in PD raised in the literature, adds value to previously covered issues, and examines areas of HR-QOL in PD that have not previously been reviewed, such as education, carer burden and surgery, highlighting where more research is warranted.

Dopamine agonists in Parkinson’s disease

Levodopa (LD), the immediate precursor of dopamine, is the most effective agent in the treatment of Parkinson's disease (PD). While quite successful in treating the primary motor deficits of PD, most patients eventually develop LD-related motor fluctuation, dyskinesias and other adverse effects associated with chronic LD therapy. There is also concern that LD is neurotoxic, although this has not been demonstrated in any in vivo studies. Dopamine agonists (DAs) have been shown to be about as effective as LD in symptomatic treatment of mild-to-moderate PD. In addition, there is a lower tendency to develop motor fluctuations and dyskinesias with DA treatment than after initiation of therapy with LD. Furthermore, there is preclinical and clinical data to suggest a slowing of neurodegeneration with DAs. The adverse effects of DAs are similar to those experienced with LD, except that the ergot agents are associated with a small risk of tissue fibrosis not noted with the non-ergot DAs.

Systematic assessment of decision models in Parkinson's disease

OBJECTIVE

To give an insight into the structural and methodological approaches used in published decision-analytic models evaluating interventions in Parkinson's disease (PD) and to derive recommendations for future comprehensive PD decision models.

METHODS

A systematic literature review was performed to identify studies that evaluated PD interventions using mathematical decision models. Using a standardized assessment form, information on the study design, methodological framework, and data sources was extracted from each publication and systematically reported. Strengths and limitations were assessed.

RESULTS

We identified eight studies that used mathematical models to evaluate different pharmaceutical (n=7) and surgical (n=1) treatment options in PD. All models included economic evaluations. Modeling approaches comprised mathematical equations, decision trees, and Markov models with a time horizon ranging from 5 years to lifetime. All based progression on the evolution of clinical surrogate endpoints. Treatment effects were either modeled via reduction of symptomatic progression and/or initial symptomatic improvement or via reduction of adverse effect rates. No model is currently available that encompasses both the underlying biologic disease progression and the spectrum of all relevant complications and also links them to patient preferences and economic outcomes.

CONCLUSIONS

Models have been successfully applied to evaluate PD treatments. However, currently available models have substantial limitations. We recommend that a comprehensive, generic, and flexible decision model for PD that can be applied to different treatment strategies should consider a large spectrum of clinically relevant outcomes and complications of the disease during a sufficiently long time horizon, include PD-specific mortality, systematically evaluate uncertainty including heterogeneity effects, and should be validated by independent data or other models. Approaches to model treatment effects included reduction of symptomatic progression, initial symptomatic improvement, or reduction of adverse effects. We believe that structural bias could be avoided if underlying disease progression and treatment effects on symptoms are modeled separately.

Treatment benefit and daily drug costs associated with treating Parkinson's disease in a Parkinson's disease clinic

OBJECTIVE

In some countries, such as Germany, there has been a move towards the treatment of patients with Parkinson's disease in specialised inpatient units. However, data on patient outcome and the daily costs of antiparkinsonian drugs in these settings are rare. This study was conducted to determine the effect of an inpatient setting (a specialised Parkinson's disease clinic) on drug therapy costs and patient symptoms.

PATIENTS AND METHODS

This study involved 63 consecutively referred inpatients of a Parkinson's disease clinic. On entry to the clinic, the patients' antiparkinsonian drug regimen was titrated in order to improve their motor function. The daily costs of drug therapy per patient (in 2002 values) were calculated, and the severity of Parkinson's disease symptoms scored via scores on the Unified Parkinson's Disease Rating Scale (UPDRS) and standardised instrumental procedures (peg insertion and tapping), both initially and at the end of the patients' stay in the clinic. The variables between the two evaluation timepoints were compared.

RESULTS

The titration of antiparkinsonian drugs was associated with a significant decrease in the symptoms of Parkinson's disease at discharge from the clinic compared with admission (as measured by UPDRS total and subscale scores [all p < 0.001], and, to a lesser extent, by peg insertion and tapping [both p < 0.05]). A significant increase in daily drug costs (an increase of euro14.11 per patient for all drugs and euro12.36 per patient for antiparkinsonian drugs [both p <0.001]) was also observed.

CONCLUSION

The results demonstrate that the symptoms experienced by patients with Parkinson's disease improve after performance of antiparkinsonian drug titration within the setting of a specialised Parkinson's disease clinic. The effect on symptoms was seen most clearly with the UPDRS, although both peg insertion and tapping reflected this improvement to a certain extent. Drug titration resulted in, on average, a doubling of daily drug costs. Future trials are needed to investigate the long-term effects of such a hospital stay on indirect costs associated with treating Parkinson's disease, and on caregiver burden, and also to compare the efficacy of a Parkinson's disease clinic with an outpatient setting.

Cabergoline versus levodopa monotherapy: a decision analysis

We evaluated the incremental cost-effectiveness of cabergoline compared with levodopa monotherapy in patients with early Parkinson's disease (PD) in the German healthcare system. The study design was based on cost-effectiveness analysis using a Markov model with a 10-year time horizon. Model input data was based on a clinical trial "Early Treatment of PD with Cabergoline" as well as on cost data of a German hospital/office-based PD network. Direct and indirect medical and nonmedical costs were included. Outcomes were costs, disease stage, cumulative complication incidence, and mortality. An annual discount rate of 5% was applied and the societal perspective was chosen. The target population included patients in Hoehn and Yahr Stages I to III. It was found that the occurrence of motor complications was significantly lower in patients on cabergoline monotherapy. For patients aged >/=60 years of age, cabergoline monotherapy was cost effective when considering costs per decreased UPDRS score. Each point decrease in the UPDRS (I-IV) resulted in costs of euro;1,031. Incremental costs per additional motor complication-free patient were euro;104,400 for patients <60 years of age and euro;57,900 for patients >/=60 years of age. In conclusion, this decision-analytic model calculation for PD was based almost entirely on clinical and observed data with a limited number of assumptions. Although costs were higher in patients on cabergoline, the corresponding cost-effectiveness ratio for cabergoline was at least as favourable as the ratios for many commonly accepted therapies.

Impact of social functioning and vitality on preference for life in patients with Parkinson's disease

The determinants of preference for life in patients with Parkinson's disease are not well known. We assessed the effect of functional status on the preference for life as measured by the time trade-off method with a 10-year life span. Our survey was based on a random sample of 1,200 patients from the Japanese Association of Patients with Parkinson's Disease. Patients' demographics, clinical information, and functional status as measured by the MOS Short Form 36 were considered independent variables. The response rate was 63.5%. Linear regression showed that men had a significantly stronger preference for current health than women (by 10.4 months on a scale of 10 years). Patients with higher physical functioning, social functioning, and vitality had significantly higher preferences for life (each 10-point improvement in physical or social functioning led to a 1.5-month increment in preference for current health; a 10-point improvement in vitality led to a 3-month increment). Longer duration of disease and advanced Hoehn and Yahr stage were significantly associated with a lower preference for current health (by 0.5 months/year of disease and by 2.6 months/stage). Interventions that target social functioning and vitality may be beneficial to preference for life.