Understanding the burden of idiopathic generalized epilepsy in the United States, Europe, and Brazil: An analysis from the National Health and Wellness Survey

Abstract

The aim of this study was to understand the current burden of primary generalized tonic-clonic seizures (PGTCS) associated with idiopathic generalized epilepsy (IGE) as a function of seizure frequency. We analyzed data for (IGE) as a proxy measure of PGTCS. Little is known about the quality of life (QoL), health utility, productivity, healthcare resource utilization (HRU), and cost burden of PGTCS or IGE. Patients were identified from the US (2011, 2012, & 2013), 5EU (2011 & 2013), and Brazil (2011 & 2012) National Health and Wellness Survey, a nationally representative, internet-based survey of adults (18+ years). Patients that self-reported a diagnosis of IGE were categorized into seizure frequencies of: ≥1 seizure per week, 1-3 seizures per month, 1-4 seizures per year, or b1 seizure per year. QoL was measured using the SF-36v2 Mental (MCS) and Physical Component Summary (PCS) scores, health utilities with the SF-6D, productivity with the Work Productivity and Activity Impairment (WPAI) questionnaire, and HRU as reported in the past six months. Unit costs were estimated from the literature and multiplied against HRU values to calculate direct costs and WPAI values to calculate indirect costs. Generalized linear regression was utilized to examine the relationship between seizure frequency and each measure of burden with adjustment for covariates. Out of the general population surveyed, IGE was self-reported in 782 of 176,093 (US), 172 of 30,000 (UK), 106 of 30,001 (Germany), 87 of 30,000 (France), 31 of 12,011 (Spain), 22 of 17,500 (Italy), and 34 of 24,000 (Brazil). Persistent seizures (≥1 per year) were reported in over 40% of patients with IGE (10-15% with ≥1 seizure per week, 10-15% with 1-3 seizures per month, 20-25% with 1-4 seizures per year). Over 75% were treated with antiepileptic drugs (AEDs). Compared with those having b1 seizure per year (reference group), patients in the two most frequent seizure categories reported worse MCS and PCS scores. Patients in the three highest seizure frequency groups consistently reported worse health utility scores, and greater presenteeism (attending work while not physically or mentally capable of working), overall work impairment, activity impairment, HRU, indirect costs, and direct costs than the reference group. Despite the availability of AEDs during the year surveyed, a substantial number of patients experienced persistent seizures. Increasing seizure frequency was clearly associated with worse outcomes. The burden of PGTCS and IGE may be proportionally reduced by newer AEDs which may increase the proportion of seizure-free patients or shift more patients into lower seizure frequency categories.

Nitrobenzylthioinosine mimics adenosine to attenuate the epileptiform discharge of hippocampal neurons from epileptic rats

“…Increased seizure frequency is exactly associated with worse outcomes and the burdens of epilepsy. Of course, new antiepileptic drugs (AEDs) may reduce these adverse events and can improve the prognosis of patients with epilepsy [5]. However, the existing AEDs fail to prevent or cure the 20-30% of epileptic patients [6, 7].…”

Understanding the burden of focal epilepsy as a function of seizure frequency in the United States, Europe, and Brazil

“…Additional stratifications for race/ethnicity distributions were performed for the United States. Additional details regarding data collection and sampling procedures are available from a similar companion study for idiopathic generalized epilepsy . The NHWS study protocol was approved by Essex IRB (Lebanon, NJ, U.S.A.).…”

“…In addition to this variable, another indirect cost variable that factored in unemployment as 100% absenteeism was created for patients ages 18–60. Further details on these measures, patient demographics, health characteristics, health outcomes, and costing methods are available in the companion study publication …”

“…Additional details regarding data collection and sampling procedures are available from a similar companion study for idiopathic generalized epilepsy. 10 The NHWS study protocol was approved by Essex IRB (Lebanon, NJ, U.S.A.). Informed consent was obtained from all participants, and participants' privacy rights were observed at all times.…”

Impaired Executive Function by Interictal Epileptiform Discharges in Patients with Idiopathic Generalized Epilepsy

“…A meta-analysis found that IGE patients demonstrated significantly lower scores on tests across all cognitive factor-domains except visual-spatial abilities [3] and increasing seizure frequency was significantly associated with worse outcomes [19]. Epilepsy is not understood as a disorder affecting one discrete brain region but as a disorder of widespread brain networks [20].…”