title: Association of antiepileptic drug nonadherence with risk of seizures in adults with epilepsy.
abstract: This study evaluated the potential effect of antiepileptic drug (AED) nonadherence on the risk of subsequent seizure. Retrospective insurance claims from the United States were analyzed. Inclusion criteria were: age 21-64 years, diagnosis of epilepsy or nonfebrile convulsions, 2 AED prescriptions, and insurance enrollment for 6 months pre- and 60 days post-AED initiation. Seizure was defined as a hospital or emergency admission associated with epilepsy or nonfebrile convulsions. Observation began 7 days post-drug initiation, ending with the first of the following: seizure, insurance disenrollment, or 365 days post-drug initiation. Adherence was measured using the medication possession ratio (MPR), with MPR <0.8 defining nonadherence. Seizure risk was assessed using an extended Cox proportional hazards model. Of 18,073 subjects identified, 2467 (14%) had 1 seizure. Mean follow-up was 133 days among subjects with event and 305 days for patients without event. Seizure risk was 21% higher among nonadherers (hazard ratio=1.205, P=0.0002) than adherers.
authors.affiliation: US Health Outcomes, Neurosciences, GlaxoSmithKline, Research Triangle Park, NC 27709, USA. ranjani.y.manjunath@gsk.com
authors.forename: Ranjani
authors.initials: R
authors.lastname: Manjunath
authors.forename: Keith L
authors.initials: KL
authors.lastname: Davis
authors.forename: Sean D
authors.initials: SD
authors.lastname: Candrilli
authors.forename: Alan B
authors.initials: AB
authors.lastname: Ettinger
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D004827:Epilepsy / Q000188:drug therapy* / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007349:Insurance, Health, Reimbursement / Q000706:statistics & numerical data; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D018570:Risk Assessment; D012640:Seizures / Q000188:drug therapy* / Q000453:epidemiology; D014481:United States; D055815:Young Adult
chemical_list: D000927:Anticonvulsants