title: Economic burden associated with the use of generic antiepileptic drugs in the United States.
abstract: This study quantifies the economic burden associated with generic-versus-branded use of antiepileptic drugs (AEDs) in the United States. Adult patients with epilepsy receiving carbamazepine, gabapentin, phenytoin, primidone, or zonisamide were selected from the PharMetrics database. By use of an open-cohort design, patients were classified into mutually exclusive periods of generic-versus-branded AED use. Annualized cost differences (CDs) between periods were estimated using multivariate regressions. Results were stratified into stable versus unstable epilepsy and newer-generation versus older-generation AEDs. A total of 33,625 patients (52% male, mean age=51 years) were observed. Periods of generic AED treatment were associated with higher medical service costs (adjusted CD [95% CI]=$3186 [$2359; $4012]), stable pharmacy costs ($69 [$-34; $171]), and greater total costs ($3254 [$2403; $4105]) versus brand use. Epilepsy-related costs represented 30% of incremental costs. Similar findings were observed for patients with stable and unstable epilepsy and users of newer-generation and older-generation AEDs. Significantly higher health care costs were observed during generic AED use across seizure control and AED subgroups.
authors.affiliation: Department of Neurology, Emory University, Atlanta, GA, USA. shelmer@emory.edu
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Helmers
authors.forename: Pierre Emmanuel
authors.initials: PE
authors.lastname: Paradis
authors.forename: Ranjani
authors.initials: R
authors.lastname: Manjunath
authors.forename: Mei Sheng
authors.initials: MS
authors.lastname: Duh
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Lafeuille
authors.forename: Dominick
authors.initials: D
authors.lastname: Latrémouille-Viau
authors.forename: Patrick
authors.initials: P
authors.lastname: Lefebvre
authors.forename: David M
authors.initials: DM
authors.lastname: Labiner
mesh_terms: D000927:Anticonvulsants / Q000191:economics* / Q000627:therapeutic use; D016208:Databases, Factual / Q000706:statistics & numerical data; D004363:Drug Utilization / Q000706:statistics & numerical data; D016568:Drugs, Generic / Q000191:economics* / Q000627:therapeutic use; D004827:Epilepsy / Q000188:drug therapy / Q000191:economics* / Q000453:epidemiology; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
chemical_list: D000927:Anticonvulsants; D016568:Drugs, Generic