title: Predictors of Pharmacy-Based Measurement and Self-Report of Antidepressant Adherence: Are Individuals Overestimating Adherence?
abstract: This study considered various factors as predictors of antidepressant adherence over time as assessed by self-report and medication possession ratios (MPRs) derived from administrative pharmacy data.
  
  
  
  Adherence was assessed at six and 12 months among 443 veterans in ongoing treatment for depression in a trial of peer support. Logistic regression models were utilized to consider predictors of adequate adherence.
  
  
  
  At six and 12 months, respectively, 36% and 35% of patients had poor adherence on the basis of MPRs and 24% and 18% had poor adherence on the basis of self-report. MPRs indicating poor adherence were more likely among men, members of racial groups other than white, and patients with Hispanic ethnicity. Poor self-reported adherence was associated with increased depressive symptoms and unemployment.
  
  
  
  These adherence measures may be complementary. Strategies to improve adherence might target specific demographic groups, unemployed persons, and persons with higher levels of depressive symptoms.
authors.affiliation: Dr. Leggett, Dr. Zivin, and Dr. Valenstein are with the Department of Psychiatry, University of Michigan Medical School, Ann Arbor (e-mail: leggetta@med.umich.edu ). Dr. Zivin and Dr. Valenstein are also with the Center for Clinical Management Research, U.S. Department of Veterans Affairs, Ann Arbor, Michigan, where Ms. Ganoczy is affiliated.
authors.forename: Amanda
authors.initials: A
authors.lastname: Leggett
authors.affiliation: Dr. Leggett, Dr. Zivin, and Dr. Valenstein are with the Department of Psychiatry, University of Michigan Medical School, Ann Arbor (e-mail: leggetta@med.umich.edu ). Dr. Zivin and Dr. Valenstein are also with the Center for Clinical Management Research, U.S. Department of Veterans Affairs, Ann Arbor, Michigan, where Ms. Ganoczy is affiliated.
authors.forename: Dara
authors.initials: D
authors.lastname: Ganoczy
authors.affiliation: Dr. Leggett, Dr. Zivin, and Dr. Valenstein are with the Department of Psychiatry, University of Michigan Medical School, Ann Arbor (e-mail: leggetta@med.umich.edu ). Dr. Zivin and Dr. Valenstein are also with the Center for Clinical Management Research, U.S. Department of Veterans Affairs, Ann Arbor, Michigan, where Ms. Ganoczy is affiliated.
authors.forename: Kara
authors.initials: K
authors.lastname: Zivin
authors.affiliation: Dr. Leggett, Dr. Zivin, and Dr. Valenstein are with the Department of Psychiatry, University of Michigan Medical School, Ann Arbor (e-mail: leggetta@med.umich.edu ). Dr. Zivin and Dr. Valenstein are also with the Center for Clinical Management Research, U.S. Department of Veterans Affairs, Ann Arbor, Michigan, where Ms. Ganoczy is affiliated.
authors.forename: Marcia
authors.initials: M
authors.lastname: Valenstein
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010594:Pharmacies / Q000706:statistics & numerical data*; D012720:Severity of Illness Index; D014478:Unemployment / Q000706:statistics & numerical data*; D014728:Veterans / Q000706:statistics & numerical data*; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D000928:Antidepressive Agents