Cost effectiveness of olanzapine in prevention of affective episodes in bipolar disorder in the United Kingdom

Designing and testing of a health-economic Markov model to assess the cost-effectiveness of treatments for Bipolar disorder: TiBipoMod

BACKGROUND

Bipolar disorder is an often recurrent mood disorder that is associated with a significant economic and health-related burden. Increasing the availability of health-economic evidence may aid in reducing this burden. The aim of this study is to describe the design of an open-source health-economic Markov model for assessing the cost-effectiveness of interventions in the treatment of Bipolar Disorders type I and II, TiBipoMod.

METHODS

TiBipoMod is a decision-analytic Markov model that allows for user-defined incorporation of both pharmacological and non-pharmacological interventions for the treatment of BD. TiBipoMod includes the health states remission, depression, (hypo)mania and death. Costs and effects are modeled over a lifetime horizon from a societal and healthcare perspective, and results are presented as the total costs, Quality-Adjusted Life Years (QALY), Life Years (LY), and incremental costs per QALYs and LYs gained.

RESULTS

Functionalities of TiBipoMod are demonstrated by performing a cost-utility analysis of mindfulness-based cognitive therapy (MBCT) compared to the standard of care. Treatment with MBCT resulted in an increase of 0.18 QALYs per patient, and a dominant incremental cost-effectiveness ratio per QALY gained for MBCT at a probability of being cost-effective of 71% when assuming a €50,000 willingness-to-pay threshold.

CONCLUSION

TiBipoMod can easily be adapted and used to determine the cost-effectiveness of interventions in the treatment in Bipolar Disorder type I and II, and is freely available for academic purposes upon request at the authors.

A Systematic Review and Critical Appraisal of Economic Evaluations of Pharmacological Interventions for People with Bipolar Disorder

BACKGROUND

Bipolar disorder (BD) is a chronic mood disorder that causes substantial psychological and financial burden. Various pharmacological treatments are effective in the management and prevention of acute episodes of BD. In an era of tighter healthcare budgets and a need for more efficient use of resources, several economic evaluations have evaluated the cost effectiveness of treatments for BD.

OBJECTIVE

The aim of this study was to systematically review and appraise published economic evaluations of pharmacological interventions for BD.

METHODS

A systematic search combining search terms specific to BD with a health economics search filter was conducted on six bibliographic databases (EMBASE, MEDLINE, PsycINFO, HTA, NHS EED, CENTRAL) in order to identify trial- or model-based full economic evaluations of pharmacological treatments of any phase of the disorder that were published between 1 January 1990 and 18 December 2015. Studies that met the inclusion criteria were critically appraised using the Quality of Health Economic Studies (QHES) checklist, and synthesised in a narrative way.

RESULTS

The review included 19 economic studies, which varied with regard to the type and number of interventions assessed, the study design, the phase of treatment (acute or maintenance), the source of efficacy data and the method for evidence synthesis, the outcome measures, the time horizon and the countries/settings in which the studies were conducted. The study quality was variable but the majority of studies were of high or fair quality.

CONCLUSION

Pharmacological interventions are cost effective, compared with no treatment, in the management of BD, both in the acute and maintenance phases. However, it is difficult to draw safe conclusions on the relative cost effectiveness between drugs due to differences across studies and limitations characterising many of them. Future economic evaluations need to consider the whole range of treatment options available for the management of BD and adopt appropriate methods for evidence synthesis and economic modelling, to explore more robustly the relative cost effectiveness of pharmacological interventions for people with BD.

Economic evaluations in bipolar disorder: a systematic review and critical appraisal

BACKGROUND

Bipolar disorder (BD) is a chronic illness and is one of the worldwide leading causes of disability. It is often a lifelong illness and incurs a substantial economic burden on the health care system, the patients, and society as a whole. However, there are few studies evaluating the economic impact of alternative strategies in the management of BD.

OBJECTIVES

We reviewed and critically appraised the available published economic evidence on BD management. In addition, we explored advantages and disadvantages of different methods used in the economic evaluation of the management of BD.

METHODS

A systematic literature search was undertaken using seven electronic databases to identify all English language articles published between January 1980 and March 2012 that provided data on complete economic evaluations for any treatment strategy for BD. The quality of included studies was appraised according to recommendations from the Cochrane Collaboration.

RESULTS

A total of 7,284 citations were obtained. After initial screening, 20 eligible studies were identified, five of which were trial-based, and 15 of which were model-based economic evaluations. Given the variability in methods and the quality of the identified studies, no conclusive recommendation for the most cost-effective therapy for BD could be provided.

CONCLUSIONS

The cost-effectiveness of different treatment strategies varied between settings, and transferability of these results across settings remains questionable. Although additional research using a longer time horizon is required to validate the findings for trial-based economic evaluations, discrete event simulation appears to be the most natural and plausible technique for modeling the cost-effectiveness of alternative BD treatment strategies.

A systematic and critical review of model-based economic evaluations of pharmacotherapeutics in patients with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a chronic and relapsing mental illness with a considerable health-related and economic burden. The primary goal of pharmacotherapeutics for BD is to improve patients' well-being. The use of decision-analytic models is key in assessing the added value of the pharmacotherapeutics aimed at treating the illness, but concerns have been expressed about the appropriateness of different modelling techniques and about the transparency in the reporting of economic evaluations.

OBJECTIVES

This paper aimed to identify and critically appraise published model-based economic evaluations of pharmacotherapeutics in BD patients.

METHODS

A systematic review combining common terms for BD and economic evaluation was conducted in MEDLINE, EMBASE, PSYCINFO and ECONLIT. Studies identified were summarised and critically appraised in terms of the use of modelling technique, model structure and data sources. Considering the prognosis and management of BD, the possible benefits and limitations of each modelling technique are discussed.

RESULTS

Fourteen studies were identified using model-based economic evaluations of pharmacotherapeutics in BD patients. Of these 14 studies, nine used Markov, three used discrete-event simulation (DES) and two used decision-tree models. Most of the studies (n = 11) did not include the rationale for the choice of modelling technique undertaken. Half of the studies did not include the risk of mortality. Surprisingly, no study considered the risk of having a mixed bipolar episode.

CONCLUSIONS

This review identified various modelling issues that could potentially reduce the comparability of one pharmacotherapeutic intervention with another. Better use and reporting of the modelling techniques in the future studies are essential. DES modelling appears to be a flexible and comprehensive technique for evaluating the comparability of BD treatment options because of its greater flexibility of depicting the disease progression over time. However, depending on the research question, modelling techniques other than DES might also be appropriate in some cases.

Cost-effectiveness of asenapine in the treatment of patients with bipolar I disorder with mixed episodes in an Italian context

INTRODUCTION

Bipolar disorder is a chronic disease characterized by periods of mania or hypomania, depression, or a combination of both (mixed state). Because bipolar disorder is one of the leading causes of disability, it represents an important economic burden on society. Asenapine (ASE) is a new second-generation antipsychotic developed and approved for the treatment of manic or mixed episodes associated with bipolar disorder. The objective of the present study was to assess the cost-effectiveness of ASE compared to olanzapine (OLA) in the treatment of patients experiencing mixed episodes associated with bipolar I disorder in the context of the Italian National Health Service (NHS).

METHODS

A pharmacoeconomic model was developed to simulate the management of Italian bipolar I patients with mixed episodes over a 5-year time horizon by combining clinical parameters with resource utilization. An expert panel of Italian psychiatrists and health economists was responsible for adapting a UK model to the Italian context. The primary outcome measure of the economic evaluation was the incremental cost effectiveness ratio, where effectiveness is measured in terms of quality adjusted life-years gained. Scenario analyses, sensitivity analyses, and a probabilistic sensitivity analysis were performed to test the robustness of the model.

RESULTS

This pharmacoeconomic model showed that ASE resulted to be dominant over OLA; in fact, ASE was associated with lower direct costs (derived largely by the savings from hospitalizations avoided) and also generated a better quality of life. Results were robust to changes in key parameters; both scenario analyses and sensitivity analyses demonstrated model reliability.

CONCLUSIONS

Results from this study suggest that the management of bipolar I patients with mixed episodes using ASE as alternative to OLA can lead to cost saving for the Italian NHS and improve patients quality of life.

Cost-effectiveness of asenapine in the treatment of bipolar I disorder patients with mixed episodes

OBJECTIVE

Around one-third of patients with bipolar I disorder (BD-I) experience mixed episodes, characterized by both mania and depression, which tend to be more difficult and costly to treat. Atypical antipsychotics are recommended for the treatment of mixed episodes, although evidence of their efficacy, tolerability, and cost in these patients is limited. This study evaluates, from a UK National Health Service perspective, the cost-effectiveness of asenapine vs olanzapine in BD-I patients with mixed episodes.

METHODS

Cost-effectiveness was assessed using a Markov model. Efficacy was informed by a post-hoc analysis of two short-term clinical trials, with response measured as a composite Young Mania Rating Score and Montgomery-Åsberg Depression Rating Scale end-point. Probabilities of discontinuation and relapse to manic, mixed, and depressive episodes were sourced from published meta-analyses. Direct costs (2012-2013 values) included drug acquisition, monitoring, and resource use related to bipolar disorder as well as selected adverse events. Benefits were measured as quality-adjusted life years (QALYs).

RESULTS

For treating mixed episodes, asenapine generated 0.0187 more QALYs for an additional cost of £24 compared to olanzapine over a 5-year period, corresponding to a £1302 incremental cost-effectiveness ratio. The higher acquisition cost of asenapine was roughly offset by the healthcare savings conferred through its greater efficacy in treating these patients. The model shows that benefits were driven by earlier response to asenapine during acute treatment and were maintained during longer-term follow-up. RESULTS were sensitive to changes in key parameters including short and longer-term efficacy, unit cost, and utilities, but conclusions remained relatively robust.

CONCLUSIONS

RESULTS suggest that asenapine is a cost-effective alternative to olanzapine in mixed episode BD-I patients, and may have specific advantages in this population, potentially leading to healthcare sector savings and improved outcomes. Limitations of the analysis stem from gaps in clinical and economic evidence for these patients and should be addressed by future clinical trials.

Cost-effectiveness of asenapine in the treatment of bipolar disorder in Canada

BACKGROUND

Bipolar disorder (BPD) is prevalent and is associated with a significant economic burden. Asenapine, the first tetracyclic antipsychotic approved in Canada for the treatment of BPD, has shown a comparable efficacy profile to other atypical antipsychotics. In addition, it is associated with a favourable metabolic profile and minimal weight gain potential. This study aimed to assess the economic impact of asenapine compared to olanzapine in the treatment of BPD in Canada.

METHODS

A decision tree combined with a Markov model was constructed to assess the cost-utility of asenapine compared with olanzapine. The decision tree takes into account the occurrence of extrapyramidal symptoms (EPS), the probability of switching to a different antipsychotic, and the probability of gaining weight. The Markov model takes into account long-term metabolic complications including diabetes, hypertension, coronary heart diseases (CHDs), and stroke. Analyses were conducted from both a Canadian Ministry of Health (MoH) and a societal perspective over a five-year time horizon with yearly cycles.

RESULTS

In the treatment of BPD, asenapine is a dominant strategy over olanzapine from both a MoH and a societal perspective. In fact, asenapine is associated with lower costs and more quality-adjusted life years (QALYs). Results of the probabilistic sensitivity analysis indicated that asenapine remains a dominant strategy in 99.2% of the simulations, in both a MoH and a societal perspective, and this result is robust to the many deterministic sensitivity analyses performed.

CONCLUSIONS

This economic evaluation demonstrates that asenapine is a cost-effective strategy compared to olanzapine in the treatment of BPD in Canada.

Cost-effectiveness of ethyl-eicosapentaenoic acid in the treatment of bipolar disorder

BACKGROUND

This study develops an economic model to evaluate the cost-effectiveness of ethyl-eicosapentaenoic acid (ethyl-EPA) as an adjunct treatment of bipolar I disorder.

METHODS

A 1-year Markov model is used incorporating three health states: euthymic, manic and depressive. The model was populated using outcomes from a clinical trial on clinical efficacy and other published literature.

RESULTS

The incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) of ethyl-EPA in comparison with placebo was estimated to be -£2,782 in 2008/09 prices, the negative ICER indicating ethyl-EPA to be a more effective and less costly treatment option than placebo in terms of cost savings of other resource use.

CONCLUSIONS

The sensitivity analysis indicated that the results were robust. Future research covering a longer time period using broader costs of the disease will be required to consolidate these findings.

Cost effectiveness of quetiapine in patients with acute bipolar depression and in maintenance treatment after an acute depressive episode

BACKGROUND

Bipolar disorder has a significant impact upon a patient's quality of life, imposing a considerable economic burden on the individual, family members and society as a whole. Several medications are indicated for the acute treatment of mania and depression associated with bipolar disorder as well as for maintenance therapy; however, these have varying efficacy, tolerability and costs.

OBJECTIVE

The objective of this study was to develop a new discrete-event simulation model to analyse the long-term consequences of pharmacological therapy for the management of bipolar I and II disorders (acute treatment of episodes of mania and depression as well as maintenance therapy).

METHODS

Probabilities of remission and relapse were obtained from clinical trial data and meta-analyses. Costs (year 2011 values) were assessed from a UK healthcare payer's perspective, and included pharmacological therapy and resource use associated with the treatment of mood events and selected adverse events. The health effects were measured in terms of QALYs.

RESULTS

For a patient starting with acute depression or in remission at 40 years of age (which was the average age in the clinical trials), quetiapine 300 mg/day was a cost-effective strategy compared with olanzapine 15 mg/day over a 5-year time frame. With acute bipolar depression as a starting episode, the 5-year medical costs were £323 higher and QALYs were 0.038 higher for quetiapine compared with olanzapine, corresponding to a cost-effectiveness ratio of £8600 per QALY gained.

CONCLUSION

Compared with olanzapine, the results suggest that quetiapine is cost effective as a maintenance treatment for bipolar depression.

Asenapine in the treatment of acute mania in bipolar I disorder: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Asenapine is indicated in adults for acute treatment of manic or mixed episodes associated with bipolar I disorder with or without psychotic features. This randomized, double-blind, placebo-controlled trial assessed the efficacy, safety, and tolerability of asenapine in bipolar I disorder.

METHODS

Adults experiencing manic or mixed episodes were randomized to 3 weeks of flexible-dose treatment with sublingual asenapine (day 1: 10mg BID, 5 or 10mg BID thereafter; n=185), placebo (n=98), or oral olanzapine (day 1: 15 mg QD, 5-20mg QD thereafter; n=205). Primary efficacy, YMRS total score change from baseline to day 21, was assessed using ANCOVA with last observation carried forward.

RESULTS

Mean daily doses were 18.4 mg asenapine and 15.9mg olanzapine. Least squares mean changes in YMRS total score on day 21 were significantly greater with asenapine than placebo (-11.5 vs -7.8; P<0.007), with advantage seen as early as day 2 (-3.2 vs -1.7; P=0.022). Changes with olanzapine on days 2 and 21 also exceeded placebo (both P<0.0001). YMRS response and remission rates with olanzapine, but not asenapine, exceeded those of placebo. Incidence of EPS-related adverse events was 10.3%, 3.1%, and 6.8% with asenapine, placebo, and olanzapine, respectively; incidence of clinically significant weight gain (7.2%; 1.2%; 19.0%). Mean weight change (baseline to endpoint) was 0.9, 0.1, and 2.6 kg with asenapine, placebo, and olanzapine, respectively.

LIMITATIONS

As this short-term study was designed for comparisons with placebo, any comparisons between asenapine and olanzapine should be interpreted cautiously.

CONCLUSIONS

Asenapine was superior to placebo in reducing YMRS total score and was well tolerated.

Cost effectiveness of adjunctive quetiapine fumarate extended-release tablets with mood stabilizers in the maintenance treatment of bipolar I disorder

BACKGROUND

Bipolar I disorder (BPD I) is a recurrent illness that affects 1% of the US population and constitutes a large economic burden. However, few studies have investigated the cost effectiveness of maintenance treatment options for BPD I.

OBJECTIVE

To determine the cost effectiveness of maintenance treatment with quetiapine fumarate extended-release (XR) tablets in combination with mood stabilizers (lithium or divalproex) in comparison with the following treatments: placebo in combination with lithium or divalproex; no maintenance treatment; lithium monotherapy; lamotrigine monotherapy; olanzapine monotherapy; and aripiprazole monotherapy.

METHODS

The analysis was conducted from the societal and payer perspectives in the US, using a Markov model. The model simulated a cohort of 1000 stabilized BPD I patients and estimated the quarterly risk in three health states: euthymia, mania and depression. Efficacy data were derived from two randomized, double-blind trials comparing quetiapine + lithium/divalproex with placebo + lithium/divalproex for up to 2 years, as well as other published literature. Resource data were extracted from published literature. Drug costs, hospitalizations and physician visits were among the direct costs. Indirect costs included absenteeism, and mortality rates included suicide. Benefits and costs were discounted at 3% and the price reference year was 2009. Endpoints included number of acute mood episodes, hospitalizations due to an acute mood event and costs per QALY. Probabilistic sensitivity analysis (PSA) was conducted to evaluate uncertainty in the model inputs.

RESULTS

Treatment with quetiapine XR + lithium/divalproex was associated with reductions in acute mania (46%), acute depression (41%) and related hospitalizations (44%) compared with placebo + lithium/divalproex, and similar reductions in events were observed relative to lithium monotherapy. In the base-case analysis from the payer perspective, the discounted incremental cost per QALY for quetiapine XR + lithium/divalproex compared with placebo + lithium/divalproex was $US22 959, and compared with lithium monotherapy was $US100 235, while all other comparators were dominated. PSA showed these results to be robust to select assumptions.

CONCLUSIONS

Quetiapine XR + lithium/divalproex may be a cost-effective maintenance treatment option for patients with BPD I.

Cost-effectiveness of quetiapine plus mood stabilizers compared with mood stabilizers alone in the maintenance therapy of bipolar I disorder: results of a Markov model analysis

OBJECTIVE

The aim of this study was to estimate the following: (1) the number of acute mood events prevented by adjunctive quetiapine therapy, and the potential cost savings; (2) the number of acute mood event-associated hospitalizations avoided by using adjunctive quetiapine therapy, and the potential cost savings of this intervention; and (3) the economic value of adjunctive quetiapine therapy in the maintenance treatment of bipolar I disorder.

METHODS

A Markov model was developed to simulate the transitions of newly stabilized adult patients with bipolar I disorder across 4 possible health states: euthymia, acute mania, acute depression, and discontinued/ no active therapy. Clinical data were obtained from 2 randomized, double-blind, Phase III trials of up to 2 years' duration (D1447C00126 and D1447C00127) that evaluated the efficacy and tolerability of quetiapine (versus placebo) when coadministered with lithium or valproate in increasing the time to recurrence of acute mood events in patients with bipolar I disorder. The model evaluated clinical and economic outcomes in 8 quarterly cycles (24 months). Outcome measures included the number of acute mood events, number of hospitalizations related to acute mood events, and their costs. Quality-adjusted life-years (QALYs) were calculated as a secondary outcome. The model was conducted from the perspective of the UK National Health Service, base year 2007.

RESULTS

In the model analysis, adjunctive quetiapine with lithium or valproate was associated with a 54% reduction in the occurrence of acute mood events, a 29% reduction in acute mood event-related hospitalization costs, and a 4% improvement in QALY gains, with 5% lower total direct costs than placebo + lithium/valproate. The incremental cost-effectiveness ratios (in year-2007 pound) were 506 per additional acute mood event avoided, 4261 per additional acute mood event-related hospitalization prevented, and -7453 per additional QALY gained. The sensitivity analyses indicated that these results were robust.

CONCLUSIONS

The results of this Markov model with a 2-year time horizon suggest that adjunctive quetiapine and mood-stabilizer therapy with lithium or valproate, compared with mood-stabilizer therapy alone in the maintenance treatment of patients with bipolar I disorder, were associated with fewer acute mood events, fewer acute mood event-related hospitalizations, and lower total costs, thereby improving patient mental health outcomes and minimizing impact on payer budgets, from the perspective of the UK National Health Service.

A 3-week, randomized, placebo-controlled trial of asenapine in the treatment of acute mania in bipolar mania and mixed states

OBJECTIVE

Asenapine is approved for bipolar disorder and schizophrenia. This was a 3-week, randomized, double-blind, placebo-controlled trial of asenapine for treating acute bipolar mania.

METHODS

After a single-blind placebo run-in period, adults (n = 488) experiencing manic or mixed episodes were randomized to flexible-dose sublingual asenapine (10 mg BID on day 1; 5 or 10 mg BID thereafter; n = 194), placebo (n = 104), or oral olanzapine (15 mg BID on day 1; 5-20 mg QD thereafter; n = 191). Primary efficacy, change in Young Mania Rating Scale (YMRS) total score from baseline to day 21, was assessed using analysis of covariance with last observation carried forward [(LOCF); primary analysis]. A mixed model for repeated measures [(MMRM); prespecified secondary analysis] was also used to assess efficacy. Tolerability and safety assessments included adverse events, physical examinations, extrapyramidal symptom ratings, and laboratory values.

RESULTS

Mean daily dosages were asenapine 18.2 mg and olanzapine 15.8 mg. Significantly greater least squares (LS) mean +/- SE changes in YMRS scores were observed on day 2 with asenapine (-3.0 +/- 0.4) and olanzapine (-3.4 +/- 0.4) versus placebo (-1.5 +/- 0.5, both p < 0.01) and were maintained until day 21 (-10.8 +/- 0.8 with asenapine, -12.6 +/- 0.8 with olanzapine; both p < or = 0.0001 versus placebo, -5.5 +/- 1.1) with LOCF. The results of MMRM analyses were consistent with those of LOCF. Asenapine had a modest impact on weight and metabolic measures.

CONCLUSIONS

These results indicate that asenapine is rapidly acting, efficacious, and well tolerated for patients with bipolar I disorder experiencing an acute manic episode.

Cost-effectiveness of quetiapine with lithium or divalproex for maintenance treatment of bipolar I disorder

BACKGROUND

Bipolar I disorder is a recurrent illness that affects 1% of the US population and constitutes a large economic burden. Few studies have investigated the cost-effectiveness of maintenance treatment options. The objective of this analysis was to assess the cost-effectiveness of quetiapine (QTP) in combination with lithium (Li) or divalproex (DVP) compared with that of Li or DVP alone for maintenance treatment of bipolar disorder.

METHODS

The cost-effectiveness of maintenance treatment with QTP in combination with Li or DVP was compared with placebo (PBO) in combination with Li or DVP from a US direct costs perspective using a Markov model. The model simulated a cohort of 1,000 stabilized patients with bipolar I disorder and estimated the quarterly risk in three health states: euthymia, mania, and depression. Efficacy data were derived from two randomized, double-blind, placebo-controlled trials comparing QTP + Li/DVP with PBO + Li/DVP for up to 2 years. Resource data were obtained from published literature. Direct costs included drug costs, hospitalizations, and physician visits. Outcomes and costs were discounted at 3% and the price reference year was 2007. Endpoints included the number of acute mood episodes, hospitalizations due to an acute mood event, and costs per quality-adjusted life-years. A probabilistic sensitivity analysis (PSA) was conducted to evaluate uncertainty.

RESULTS

In the base-case analysis, QTP + Li/DVP dominated PBO + Li/DVP. The PSA showed these results to be robust. In addition, treatment with QTP + Li/DVP was associated with reductions in acute manic episodes (46%), acute depressive episodes (41%), and related hospitalizations (44%) compared with PBO + Li/DVP.

CONCLUSIONS

These analyses, based on two randomized clinical trials, suggest that QTP + Li/DVP is a cost-effective maintenance treatment option for patients with bipolar I disorder compared with Li or DVP alone.