title: Untangling the relationship between medication adherence and post-myocardial infarction outcomes: medication adherence and clinical outcomes.
abstract: BACKGROUND
  Patients who adhere to medications experience better outcomes than their nonadherent counterparts. However, these observations may be confounded by patient behaviors. The level of adherence necessary for patients to derive benefit and whether adherence to all agents is important for diseases that require multiple drugs remain unclear. This study quantifies the relationship between medication adherence and post-myocardial infarction (MI) adverse coronary events.
  
  
  METHODS
  This is a secondary analysis of the randomized MI FREEE trial. Patients who received full prescription coverage were classified as adherent (proportion of days covered ≥80%) or not based upon achieved adherence in the 6 months after randomization. First major vascular event or revascularization rates were compared using multivariable Cox models adjusting for comorbidity and health-seeking behavior.
  
  
  RESULTS
  Compared with patients randomized to usual care, full coverage patients adherent to statin, β-blocker, or angiotensin-converting enzyme inhibitor/angiotensin receptor blocker were significantly less likely to experience the study's primary outcome (hazard ratio [HR] range 0.64-0.81). In contrast, nonadherent patients derived no benefit (HR range 0.98-1.04, P ≤ .01 for the difference in HRs between adherent and nonadherent patients). Partially adherent patients had no reduction in clinical outcomes for any of the drugs evaluated, although their achieved adherence was higher than that among controls.
  
  
  CONCLUSIONS
  Achieving high levels of adherence to each and all guideline-recommended post-MI secondary prevention medication is associated with improved event-free survival. Lower levels of adherence appear less protective.
authors: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA. Electronic address: nchoudhry@partners.org.
authors: Niteesh K
authors: NK
authors: Choudhry
authors: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Department of Medicine, Division of Preventive Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: Robert J
authors: RJ
authors: Glynn
authors: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: Jerry
authors: J
authors: Avorn
authors: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: Joy L
authors: JL
authors: Lee
authors: CVS Caremark, Woonksocket, RI.
authors: Troyen A
authors: TA
authors: Brennan
authors: Aetna, Hartford, CT.
authors: Lonny
authors: L
authors: Reisman
authors: Aetna, Hartford, CT.
authors: Michele
authors: M
authors: Toscano
authors: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: Raisa
authors: R
authors: Levin
authors: CVS Caremark, Woonksocket, RI.
authors: Olga S
authors: OS
authors: Matlin
authors: Department of Medicine, Division of Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: Elliott M
authors: EM
authors: Antman
authors: Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: William H
authors: WH
authors: Shrank
mesh_terms: D057911:Angiotensin Receptor Antagonists / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D019983:Guideline Adherence; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D019458:Insurance Coverage; D009203:Myocardial Infarction / Q000150:complications / Q000188:drug therapy* / Q000191:economics / Q000401:mortality / Q000517:prevention & control; D009204:Myocardial Revascularization; D017410:Practice Guidelines as Topic; D055502:Secondary Prevention; D016903:Drug Monitoring
chemical_list: D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors