title: Adherence to antiepileptic drugs among diverse older Americans on Part D Medicare.
abstract: Older minority groups are more likely to have poor AED adherence. We describe adherence to antiepileptic drugs (AEDs) among older Americans with epilepsy.
  
  
  
  In retrospective analyses of 2008-2010 Medicare claims for a 5% random sample of beneficiaries augmented by minority representation, epilepsy cases in 2009 were those with ≥1 claim with ICD-9345.x or ≥2 with 780.3x, and ≥1 AED. New-onset cases had no such claims or AEDs in the year before the 2009 index event. We calculated the Proportion of Days Covered (PDC) (days with ≥1 AED over total follow-up days) and used logistic regression to estimate associations of non-adherence (PDC <0.8) with minority group adjusting for covariates.
  
  
  
  Of 36,912 epilepsy cases (19.2% White, 62.5% African American (AA), 11.3% Hispanic, 5.0% Asian and 2% American Indian/Alaskan Native), 31.8% were non-adherent (range: 24.1% Whites to 34.3% AAs). Of 3706 new-onset cases, 37% were non-adherent (range: 28.7% Whites to 40.5% AAs). In adjusted analyses, associations with minority group were significant among prevalent cases, and for AA and Asians vs. Whites among new cases. Among other findings, beneficiaries from high-poverty ZIP codes were more likely to be non-adherent than their counterparts, and those in cost-sharing drug benefit phases were less likely to be non-adherent than those in deductible phases.
  
  
  
  About a third of older adults with epilepsy have poor AED adherence; minorities are more likely than Whites. Investigations of reasons for non-adherence, and interventions to promote adherence, are needed with particular attention to the effect of cost-sharing and poverty.
authors.affiliation: Department of Gynecology and Obstetrics, Emory University, United States. Electronic address: kendra.piper@emory.edu.
authors.forename: Kendra
authors.initials: K
authors.lastname: Piper
authors.affiliation: Department of Surgery, University of Alabama at Birmingham, United States. Electronic address: jrichman@uabmc.edu.
authors.forename: Joshua
authors.initials: J
authors.lastname: Richman
authors.affiliation: Department of Neurology, Emory University, United States. Electronic address: rfaught@emory.edu.
authors.forename: Edward
authors.initials: E
authors.lastname: Faught
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, United States. Electronic address: rmartin@uabmc.edu.
authors.forename: Roy
authors.initials: R
authors.lastname: Martin
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham, United States. Electronic address: efunkhouser@uabmc.edu.
authors.forename: Ellen
authors.initials: E
authors.lastname: Funkhouser
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, United States. Electronic address: jszaflarski@uab.edu.
authors.forename: Jerzy P
authors.initials: JP
authors.lastname: Szaflarski
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham, United States. Electronic address: chendai@uabmc.edu.
authors.forename: Chen
authors.initials: C
authors.lastname: Dai
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham, United States. Electronic address: ljuarez@uabmc.edu.
authors.forename: Lucia
authors.initials: L
authors.lastname: Juarez
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham, United States. Electronic address: mpisu@uab.edu.
authors.forename: Maria
authors.initials: M
authors.lastname: Pisu
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000191:economics / Q000627:therapeutic use*; D015331:Cohort Studies; D003362:Cost-Benefit Analysis / Q000379:methods; D004827:Epilepsy / Q000188:drug therapy* / Q000208:ethnology* / Q000523:psychology; D005006:Ethnicity / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D054524:Medicare Part D / Q000191:economics / Q000639:trends*; D055118:Medication Adherence / Q000208:ethnology* / Q000523:psychology; D012189:Retrospective Studies; D014481:United States / Q000208:ethnology
chemical_list: D000927:Anticonvulsants
keywords: Adherence; Epilepsy; Medicare; Older adults; Part D coverage