The prevalence of epilepsy amongst autistic children is around 7%, rising to 26% in adolescents, in comparison to 1% prevalence in the general population (El Achkar & Spence,
2015; Liu et al.,
2022; Zack & Kobau,
2017). Epilepsy has been identified as a leading cause of premature mortality for autistic people (Hirvikoski et al.,
2016). Co-occurring epilepsy and autism present greater challenges for clinicians in identifying and treating epilepsy, particularly if someone also has intellectual disabilities (Besag,
2017). Recommended treatments for medical conditions which co-occur with autism (such as epilepsy) are largely similar for both autistic and non-autistic people (National Clinical Guideline Centre,
2012), but the effectiveness and cost-effectiveness of treatment may be different for autistic people compared to the neurotypical population. This is potentially the case for epilepsy, since childhood and adolescent onset are associated with above-average use of long-term healthcare resources, and there may also be long-term negative impacts on education level, employment status, and earned income (Hunter et al.,
2015; Jennum et al.,
2016; Knapp et al.,
2015; Snell et al.,
2013).
The National Institute for Health and Care Excellence (NICE) was established in England in 1999 to review available clinical, economic and other evidence to develop guidelines for the (tax-funded) National Health Service (NHS). NICE is a non-departmental public body funded by the government, but independent in its role of developing guidelines. In 2021, NICE updated guidance on the diagnosis and management of epilepsies (NICE,
2021). This guidance applies to the overall population of people living with epilepsy, and not specifically to autistic individuals. The purpose of the study described in this paper is to examine whether recommended treatments have different effects and costs for autistic people with epilepsy. We also aim to examine a wider set of impacts on society (family out-of-pocket expenses, work productivity and informal/unpaid care), since although NICE does not look beyond the health and social care system, autism often has wide-ranging impacts.
We explore the cost-effectiveness of antiepileptic drugs in treating autistic children in four countries with different healthcare systems and practices – England, Ireland, Italy and Spain. An important consideration is that, unlike for a neurotypical population, family impacts (and associated costs) can be sizeable (Buescher et al.,
2014). It is therefore important to examine the widest range of costs and effects (if data allow). Our study is part of the [name deleted to maintain the integrity of the review process] project (reference deleted to maintain the integrity of the review process).
Discussion
Our study provides evidence of the cost-effectiveness of antiepileptic drugs in treating autistic children in four countries with different healthcare systems and practices (England, Ireland, Italy and Spain). A clear finding, based on the effectiveness and cost-effectiveness calculations, is that carbamazepine is the optimal drug to try first in children with newly diagnosed focal seizures. For England and Spain, oxcarbazepine is potentially the most cost-effective adjunctive AED. In Ireland and Italy, gabapentin is the preferred option. Our analysis highlights the substantial economic impact on families with an autistic child who has epilepsy, which is considerably higher than healthcare expenditure.
Our study has both strengths and weaknesses. The cost-effectiveness analysis was based on a robust model developed by NICE for England and adapted, with the support of experts, to measure the impact on healthcare providers across different country settings. Due to the paucity of data available for autistic children with epilepsy, we assumed that the economic model of pharmacological treatments for children with focal epilepsy used by NICE would apply to autistic children with focal epilepsy. The modelling describes the treatment pathway for focal seizures. Although focal types are the most common in children with epilepsy, this may limit the model’s relevance for autistic children with other types of epilepsy. Also, the parameters for the healthcare model rely heavily on the NICE model. Demographic characteristics such as family income, parental education, comorbidity, or degree of autism are possible influences on QALYs, but the NICE model is based on randomised controlled trials and the methodology of randomisation would have wiped out their effects. Importantly, this is the first study to estimate the extra economic impact on families where there is an autistic child on epilepsy medication in comparison to autistic children without epilepsy. Our findings highlight the extra costs and challenges (related to out-of-pocket expenditure, lost earnings and informal care costs) faced by these families in comparison to the neurotypical population. (The NICE model did not look at family costs when considering the cost-effectiveness of anti-epileptic medication.) It should be noted, however, that the only relevant data set available to us included only seven autistic children with epilepsy on medication. There is only one female within this subgroup in the sample, therefore it was not possible to do an analysis based on gender and we acknowledge this is a limitation of the paper. While Samba Reddy (
2017) acknowledges there are gender differences in the susceptibility to seizures, Perucca et al. (
2014) found that there is not sufficient evidence to support considerable changes in the efficacy of AEDs due to gender. In relation to potential sample bias, the Irish survey cost data may not be representative of all families with an autistic child in Ireland. However, we are unable to determine whether this leads to any bias in the results.
Previous literature on the cost-effectiveness of epilepsy medication has focused entirely on the neurotypical adult population (Allers et al.,
2015; Wijnen et al.,
2017; NICE,
2021). Even then, the number of economic evaluations focused on children is very limited (Lee et al.,
2013,
2014; Widjaja et al.,
2021; NICE,
2021) and none of them looked at implications for autistic people. Healthcare costs vary along the care pathway for epilepsy and are mainly driven by hospitalization costs, followed by specialist (outpatient) visits and medications (Widjaja et al.,
2021). Following the literature, hospitalisations accounted for the largest proportion of costs for pre-diagnosis, initial intervention and final care. For ongoing care (described in our model), previous studies and our own analyses show that costs related to specialist (outpatient) visits are one of the main cost-drivers as well as medication costs. Remote consultations with healthcare professionals could secure efficiency gains for the healthcare provider by reducing waiting times and unnecessary appointments for patients who are seeking access to specialist outpatient services (Almathami et al.,
2020). They could also secure better outcomes for children, avoid the stress of travel and the busy and noisy environment of a clinic as children could have the consultation in their own safe space (Autistica,
2022). This would bring additional economic savings for their families, cutting down time spent travelling and away from their employment.
The wider literature shows that families with autistic children often experience considerable extra costs, lost earnings and increased caring demands due to their child’s additional needs (Barrett et al.,
2012; Buescher et al.,
2014; Dillenburger et al.,
2015; Hussain et al.,
2020; Järbrink et al.,
2000; additional reference deleted to maintain the integrity of the review process). A national survey conducted in Ireland found that the average annual cost per autistic child for families was €28,465 because of out-of-pocket expenditure on private autism services, lost income and informal care (reference deleted to maintain the integrity of the review process).
Age is a major influence on family costs for children with epilepsy – costs are higher for older children – but less so for those with no epilepsy (Argumosa et al.,
2004). Epilepsy is a chronic neurological disorder that not only has economic impacts but also may have major effects on individual social competence and family relationships (Jennum et al.,
2016). This may be even more pronounced in older children and young adults (compared with younger children) for whom the disorder influences self-perception (Hirfanoglu et al.,
2009), stigma (Jacoby et al.,
2007), education (Fleming et al.,
2019) employment (Jennum et al.,
2011), social prognosis, and income. Also, there is evidence that children with epilepsy have higher welfare costs compared with people without epilepsy (regardless of comorbid disorders; Jennum et al.,
2016).
Our findings have implications for policy and practice. Treating autistic children with epilepsy with medication is cost-effective for the healthcare provider. Carbamazepine, which is widely recommended as a first-line antiepileptic drug for new-onset partial seizures with or without generalization (NICE,
2021), was the preferred monotherapy option for all countries. It presented the lowest proportion of medicine costs (varying between 2% and 20%) across countries. However, different strategies may be needed in different countries for adjunctive therapy. The preferred options (oxcarbazepine for England and Spain and gabapentin for Ireland and Italy, respectively) presented a lower proportion of medicines costs (between 16% and 22%) compared with other options (where the costs of the medicines reached up to 59% of the total costs, as reported by lamotrigine and oxcarbazepine for Italy).
In Ireland, long-term family costs for autistic children treated for their focal epilepsy (€441,505 for 15 years) are likely to be 46 times more than costs borne by healthcare providers: either €9,658 for children on monotherapy with carbamazepine or €7,128 for those on adjunctive therapy with gabapentin. From a family perspective, it is important to understand the lived experience and complexity of the needs involved in caring for an autistic child or adolescent with epilepsy, linked to the unpredictability and frequency of seizures. These needs and uncertainties create extra caring demands which may directly affect the ability of parents to sustain employment if they need to take time off to support and monitor their child and accompany them to medical appointments. We also found that families with autistic children on epilepsy medication had high out-of-pocket expenditures perhaps because of hospital visits or payment for privately paid neurologists and other appointments (due to long waiting lists). Taking family costs into account when considering the economic case for treatment can sometimes alter the recommended decision (Lavelle et al.,
2019).
Acknowledgements
Funding for this work was supported by the European Brain Council as part of the Value of Treatment Project. Dr. Arango has received support by the Spanish Ministry of Science and Innovation. Instituto de Salud Carlos III, co-financed by ERDF Funds from the European Commission, “A way of making Europe”, CIBERSAM. Madrid Regional Government (B2017/BMD-3740 AGES-CM-2), European Union Structural Funds and European Union H2020 Program under the Innovative Medicines Initiative 2 Joint Undertaking (grant agreement No 115916, Project PRISM, and grant agreement No 777394, Project AIMS-2-TRIALS), Fundación Familia Alonso and Fundación Alicia Koplowitz. Dr Oakley received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 777394 (for AIMS-2-TRIALS). This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA and AUTISM SPEAKS, Autistica, SFARI. Any views expressed are those of the author(s) and not necessarily those of the funders.
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