Economic Evaluation of Add-on Levetiracetam for the Treatment of Refractory Partial Epilepsy in Korea

Levetiracetam for epilepsy: an evidence map of efficacy, safety and economic profiles

OBJECTIVE

To evaluate the efficacy, safety and economics of levetiracetam (LEV) for epilepsy.

MATERIALS AND METHODS

PubMed, Scopus, the Cochrane Library, OpenGrey.eu and ClinicalTrials.gov were searched for systematic reviews (SRs), meta-analyses, randomized controlled trials (RCTs), observational studies, case reports and economic studies published from January 2007 to April 2018. We used a bubble plot to graphically display information of included studies and conducted meta-analyses to quantitatively synthesize the evidence.

RESULTS

A total of 14,803 records were obtained. We included 30 SRs/meta-analyses, 34 RCTs, 18 observational studies, 58 case reports and 2 economic studies after the screening process. The included SRs enrolled patients with pediatric epilepsy, epilepsy in pregnancy, focal epilepsy, generalized epilepsy and refractory focal epilepsy. Meta-analysis of the included RCTs indicated that LEV was as effective as carbamazepine (CBZ; treatment for 6 months: 58.9% vs 64.8%, OR=0.76, 95% CI: 0.50-1.16; 12 months: 54.9% vs 55.5%, OR=1.24, 95% CI: 0.79-1.93), oxcarbazepine (57.7% vs 59.8%, OR=1.34, 95% CI: 0.34-5.23), phenobarbital (50.0% vs 50.9%, OR=1.20, 95% CI: 0.51-2.82) and lamotrigine (LTG; 61.5% vs 57.7%, OR=1.22, 95% CI: 0.90-1.66). SRs and observational studies indicated a low malformation rate and intrauterine death rate for pregnant women, as well as low risk of cognitive side effects. But psychiatric and behavioral side effects could not be ruled out. LEV decreased discontinuation due to adverse events compared with CBZ (OR=0.52, 95% CI: 0.41-0.65), while no difference was found when LEV was compared with placebo and LTG. Two cost-effectiveness evaluations for refractory epilepsy with decision-tree model showed US$ 76.18 per seizure-free day gained in Canada and US$ 44 per seizure-free day gained in Korea.

CONCLUSION

LEV is as effective as CBZ, oxcarbazepine, phenobarbital and LTG and has an advantage for pregnant women and in cognitive functions. Limited evidence supports its cost-effectiveness.

REGISTERED NUMBER

PROSPERO (No CRD 42017069367).

Assessment of components included in published societal perspective or QALY outcome economic analyses for antiepileptic drug treatment in chronic epilepsy

INTRODUCTION

Antiepileptic drug (AED) treatments seek to control seizures with minimal or no adverse effects, effects which can substantially impact costs and outcomes for patients, caregivers, and third party payers. The First and Second Panel on Cost-Effectiveness in Health and Medicine recommend inclusion of a societal reference case, even in studies conducted from a healthcare sector perspective, for comparability of findings across studies. Cost and outcome evaluation components include direct medical, non-direct medical-related (e.g. patient-time and transportation costs for treatment) and non-healthcare sectors (e.g. lost productivity).

AREAS COVERED

Guided by Second Panel recommendations, this review developed an overall impact inventory and detailed adverse effect impact inventory to assess the scope and methods in published economic evaluations of AED treatments for adults with chronic epilepsy. Societal perspective evaluations or evaluations that utilized quality-adjusted life-years (QALYs) as an outcome were reviewed. The majority of reviewed articles were healthcare sector perspective studies, methods for estimating QALYs varied widely, and a minority considered specific AED treatment adverse effects.

EXPERT COMMENTARY

Only considering a healthcare sector perspective fails to provide full information for patients on AED treatments. Using an impact inventory to guide study scope and design will facilitate full reporting of costs and benefits.

A systematic review of economic evaluations of treatments for patients with epilepsy

The increasing number of treatment options and the high costs associated with epilepsy have fostered the development of economic evaluations in epilepsy. It is important to examine the availability and quality of these economic evaluations and to identify potential research gaps. As well as looking at both pharmacologic (antiepileptic drugs [AEDs]) and nonpharmacologic (e.g., epilepsy surgery, ketogenic diet, vagus nerve stimulation) therapies, this review examines the methodologic quality of the full economic evaluations included. Literature search was performed in MEDLINE, EMBASE, NHS Economic Evaluation Database (NHS EED), Econlit, Web of Science, and CEA Registry. In addition, Cochrane Reviews, Cochrane DARE and Cochrane Health Technology Assessment Databases were used. To identify relevant studies, predefined clinical search strategies were combined with a search filter designed to identify health economic studies. Specific search strategies were devised for the following topics: (1) AEDs, (2) patients with cognitive deficits, (3) elderly patients, (4) epilepsy surgery, (5) ketogenic diet, (6) vagus nerve stimulation, and (7) treatment of (non)convulsive status epilepticus. A total of 40 publications were included in this review, 29 (73%) of which were articles about pharmacologic interventions. Mean quality score of all articles on the Consensus Health Economic Criteria (CHEC)-extended was 81.8%, the lowest quality score being 21.05%, whereas five studies had a score of 100%. Looking at the Consolidated Health Economic Evaluation Reporting Standards (CHEERS), the average quality score was 77.0%, the lowest being 22.7%, and four studies rated as 100%. There was a substantial difference in methodology in all included articles, which hampered the attempt to combine information meaningfully. Overall, the methodologic quality was acceptable; however, some studies performed significantly worse than others. The heterogeneity between the studies stresses the need to define a reference case (e.g., how should an economic evaluation within epilepsy be performed) and to derive consensus on what constitutes "standard optimal care."

Cost-utility analysis of competing treatment strategies for drug-resistant epilepsy in children with Tuberous Sclerosis Complex

BACKGROUND

The management of drug-resistant epilepsy in children with Tuberous Sclerosis Complex (TSC) is challenging because of the multitude of treatment options, wide range of associated costs, and uncertainty of seizure outcomes. The most cost-effective approach for children whose epilepsy has failed to improve with first-line medical therapy is uncertain.

METHODS

A review of MEDLINE from 1990 to 2015 was conducted. A cost-utility analysis, from a third-party payer perspective, was performed for children with drug-resistant epilepsy that had failed to improve with 2 antiseizure drugs (ASDs) and that was amenable to resective epilepsy surgery, across a time-horizon of 5years. Four strategies were included: (1) resective epilepsy surgery, (2) vagus nerve stimulator (VNS) implantation, (3) ketogenic diet, and (4) addition of a third ASD (specifically, carbamazepine). The incremental cost per quality-adjusted life year (QALY) gained was analyzed.

RESULTS

Given a willingness-to-pay (WTP) of $100,000 per QALY, the addition of a third ASD ($6600 for a gain of 4.14 QALYs) was the most cost-effective treatment strategy. In a secondary analysis, if the child whose epilepsy had failed to improve with 3 ASDs, ketogenic diet, addition of a fourth ASD, and resective epilepsy surgery were incrementally cost-effective treatment strategies. Vagus nerve stimulator implantation was more expensive yet less effective than alternative strategies and should not be prioritized.

CONCLUSIONS

The addition of a third ASD is a universally cost-effective treatment option in the management of children with drug-resistant epilepsy that has failed to improve with 2 ASDs. For children whose epilepsy has failed to improve with 3 ASDs, the most cost-effective treatment depends on the health-care resources available reflected by the WTP.

The cost effectiveness of newer epilepsy treatments: a review of the literature on partial-onset seizures

BACKGROUND AND OBJECTIVE

Epilepsy is one of the most common neurological disorders, affecting more than 3 million people in Europe. This paper reviews the published evidence regarding the cost effectiveness of second-generation antiepileptic drugs (AEDs).

METHODS

A systematic literature search was performed, using the databases Academic Search Complete, Econlit, EMBASE and MEDLINE. Health economic evaluations of newer (second-generation) AEDs, published as full-length journal articles, were searched for. We focused on evaluations of newer AEDs as treatment for partial-onset seizures. 470 studies were initially identified and 19 were finally included. Information regarding (i) AEDs studied, (ii) cost effectiveness, and (iii) a variety of health economic modelling specifics was extracted from each study. Then, the included studies were summarized and a quality assessment was performed, according to the British Medical Journal's guidelines for economic studies.

RESULTS

The results were as follows: (i) the cost per additional QALY for newer AEDs used as adjunctive treatment, compared with standard therapy, ranged between $US19 139 (levetiracetam) and $US57 210 (pregabalin) [year 2010 values]; no cost-effectiveness evidence was identified for felbamate, eslicarbazepine, oxcarbazepine or tiagabine; and (ii) all studies met at least 60% of the British Medical Journal's guidelines criteria, and seven studies were found to satisfy more than 80% of the criteria. Guidelines criteria not met involve inadequate reporting of input data and modelling details, including validation and availability of models used for cost-effectiveness calculations.

CONCLUSIONS

Although failure to meet good practice guidelines influences the reliability of the presented evidence adversely, a sufficient number of the included studies were found to comply enough with the guidelines in order for the qualitative content of the cost-effectiveness results - that some of the newer AEDs are cost effective - to be reliable. In fact, this conclusion is likely to be relatively robust, since the effect of improved seizure control on labour market performance was not included in the base-case results in any of the included studies and improved seizure control need only to have a moderate effect on sickness absenteeism in order for the corresponding treatment to be cost effective even when willingness to pay for an additional QALY is low. However, the cost effectiveness of newer AEDs has only been studied for a small number of settings, and hence future studies incorporating additional settings are needed.

A comprehensive review of the literature on epilepsy in selected countries in emerging markets

AIMS

To perform a systematic literature review of studies in peer reviewed journals on the epidemiology, economics, and treatment patterns of epilepsy in selected countries in emerging markets.

METHODS

A literature search was performed using relevant search terms to identify articles published from 1999 to 2000 on the epidemiology, economics, and treatment patterns of epilepsy. Studies were identified through electronic Embase(®), Cochrane(©), MEDLINE(®), and PubMed(®) databases. Manual review of bibliographies allowed for the detection of additional articles.

RESULTS

Our search yielded 65 articles. These articles contained information relevant to epidemiology (n = 16), treatment guidelines (n = 4), treatment patterns (n = 33), unmet needs (n = 4), and economics (n = 8). From a patient perspective, patients with less than or equal to two adverse events (AEs) while taking anti-epileptic drugs (AEDs) had significantly lower annual costs than those having greater than or equal to three AEs, as did patients with fewer seizures. The overall mean annual cost for epilepsy per patient ranged from US$773 in China to US$2646 in Mexico. Prevalence data varied widely and were found for countries including Arab League Members, China, India, and Taiwan. In Turkey, active prevalence rates ranged from 0.08/1000 to 8.5/1000, and in Arab countries, active prevalence ranged from 0.9/1000 in Sudan to 6.5/1000 in Saudi Arabia. Seventeen different AEDs were used in the identified studies. The most common AEDs utilized were phenobarbital (21.7%), valproate (17.5%), and tiagabine (16.4%). In all studies, the use of AEDs resulted in an increase of patients who became seizure free and a reduction in seizure frequency and severity.

CONCLUSION

Few studies have examined the prevalence and incidence of epilepsy in emerging markets and study limitations tend to underestimate these rates at all times. More cost-effectiveness, cost-minimization, and cost-benefit analyses must be performed to enhance the data on the economics of epilepsy and its therapy in regions with insufficient resources and those emerging markets which contain the majority of the world's population. And finally, the study found that generic AEDs are frequently used to successfully treat patients with epilepsy in emerging markets.