title: Effect of exposure to evidence-based pharmacotherapy on outcomes after acute myocardial infarction in older adults.
abstract: OBJECTIVE
  To assess the effect of exposure to evidence-based medication after hospital discharge for Medicare beneficiaries with acute myocardial infarction (AMI).
  
  
  METHODS
  A discrete-time hazard model was used to estimate time to outcome associated with exposure to four drug classes (angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin-II receptor blockers (ARBs), beta-blockers (BBs), statins, and clopidogrel) used for post-AMI secondary prevention of cardiovascular events and mortality.
  
  
  METHODS
  Medicare administrative data for a 5% random sample of beneficiaries.
  
  
  METHODS
  Medicare beneficiaries (N = 9,538) hospitalized for an AMI between April 1, 2006, and December 31, 2007, who survived for at least 30 days after discharge. The cohort was followed until death or December 31, 2008.
  
  
  METHODS
  Time-varying exposure was measured as proportion of days covered (PDC) for each quarter during the follow-up period. PDC was classified into five categories (0-0.2, 0.2-0.4, 0.4-0.6, 0.6-0.8, 0.8-1.0). Outcomes were mortality and a composite outcome of death or post-AMI hospitalization.
  
  
  RESULTS
  Over a median follow-up of 18 months, mean PDC rates ranged from 0.37 (clopidogrel) to 0.50 (statins). When comparing the highest versus lowest categories of exposure, the hazard of the composite outcome was significantly lower for all drug classes except BBs (statins, adjusted hazard ratio (aHR) = 0.71, ACEIs/ARBs, aHR = 0.81, clopidogrel, aHR = 0.85, BBs, aHR = 0.93). All four drug classes were significantly associated with reductions in mortality; the magnitude of effect for the mortality outcome was largest for statins and smallest for BBs. Age modified the effect of statins on mortality.
  
  
  CONCLUSIONS
  Use of evidence-based medications for secondary prevention after AMI is suboptimal in the Medicare population, and low exposure rates are associated with significantly higher risk for subsequent hospitalization and death.
authors.affiliation: Department of Pharmaceutical Health Services Research, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA. izuckerm@rx.umaryland.edu
authors.forename: Ilene H
authors.initials: IH
authors.lastname: Zuckerman
authors.forename: Xianghua
authors.initials: X
authors.lastname: Yin
authors.forename: Gail B
authors.initials: GB
authors.lastname: Rattinger
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Gottlieb
authors.forename: Linda
authors.initials: L
authors.lastname: Simoni-Wastila
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Pierce
authors.forename: Ting-Ying
authors.initials: TY
authors.lastname: Huang
authors.forename: Rahul
authors.initials: R
authors.lastname: Shenolikar
authors.forename: Bruce
authors.initials: B
authors.lastname: Stuart
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000009:adverse effects; D000368:Aged; D000369:Aged, 80 and over; D047228:Angiotensin II Type 1 Receptor Blockers / Q000009:adverse effects; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects; D018890:Chemoprevention / Q000009:adverse effects; D000077144:Clopidogrel; D055317:Evidence-Based Practice; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000517:prevention & control*; D055502:Secondary Prevention; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine