Seizure 2022, Vol 97, Editor’s Choice: The influence of demographics and comorbidity on persistence with anti-seizure medication
The regular ingestion of antiseizure medicines (ASMs) continues to be the mainstay of epilepsy treatment. With optimal use, ASM treatment should allow seven out of every ten people with epilepsy (PWE) to achieve full seizure control. While epilepsy is not always a lifelong disease, ASM treatment typically has to be continued for several years to achieve and maintain seizure control and to protect PWE from the harms of uncontrolled seizures, including injury, disability, and death. Unfortunately, in reality – even in countries like the UK where access to diagnostic and treatment facilities and the full range of ASMs are available to PWE free of charge - the proportion of individuals who actually achieve full control of their seizures has been estimated to be as low as 50% (1).
Non-adherence with ASMs is likely to make an important contribution to the gap between what medication could achieve in an ideal world and what it does achieve in reality. A systematic review previously published in Seizure related non-adherence to specific beliefs about medications, comorbid depression and anxiety, poor medication self-administration management, uncontrolled recent seizures, frequent medication dosage times, poor physician-patient relationship and social support (2).
My editor’s choice from the current volume of Seizure is a research study by Alex D. Marshall et al. using routinely available health service data from a total of 6,449 patients to explore one particular manifestation of non-adherence: the non-persistence with a newly started ASM (3). The authors focussed particularly on the effects of sociodemographic variables and comorbidities but also looked at the effects of ASM choice on persistence. The most striking finding is that only 45% of patients who were started on a first ASM after they had received a diagnosis of epilepsy persisted for at least one year. Persistence rates were not higher in the 46% of patients who received a second ASM during the eight-year study period. Almost 10% of patients never persisted with any ASM for at least one year. Persistence for at least three months ranged from 25.7% to 78.6% between different ASMs, with lacosamide, lamotrigine and levetiracetam faring much better than carbamazepine or topiramate. To some extent, non-persistence may have reflected the efforts of clinicians to achieve seizure control with as few side effects as possible. However, the fact that persistence was significantly lower in younger people and those who had previously been nonpersistent with ASMs suggests that attitudes towards medication taking, risk, social and educational factors may also have been relevant.
While the investigation of routinely collected healthcare data often raises questions which need to answered with research using other methods, this paper demonstrates that epilepsy management models restricting the input of specialist service to the diagnosis and prescription of a first ASM are likely to fail the many PWE who need more time, education and expert input after the diagnosis of epilepsy and before they have found a treatment that suits them and that they are able and willing to take.
(1) Joint Epilepsy Council of the UK and Ireland. Epilepsy prevalence, incidence and other statistics, 2011. https://d3imrogdy81qei.cloudfront.net/instructor_docs/373/29_05_2016_Joint_Epilepsy_Council_Prevalence_and_Incidence_September_11.pdf
(2) O'Rourke G, O'Brien JJ. Identifying the barriers to antiepileptic drug adherence among adults with epilepsy. Seizure-European Journal of Epilepsy 2017;45:160-8.Sperling MR, Barshow S, Nei M, Asadi-Pooya AA. A reappraisal of mortality after epilepsy surgery. Neurology 2016 24;86:1938-44.
(3) Marshall AD, Pell JP, Askarieh A, Leach JP, Heath C. The influence of demographics and comorbidity on persistence with anti-seizure medication. Seizure 2022; 97:88-93.