title: Adherence and persistence with prasugrel following acute coronary syndrome with percutaneous coronary intervention.
abstract: OBJECTIVE
  To measure the adherence and persistence of patients with acute coronary syndrome (ACS) initiating prasugrel after percutaneous coronary intervention (PCI).
  
  
  METHODS
  Using the Thomson Reuters MarketScan Commercial and Medicare Supplemental database, a retrospective cohort study identified patients initiating prasugrel following ACS-PCI hospitalization in 2009-2011. Prasugrel adherence over 12 months was measured using the medication possession ratio (MPR); predictors of adherence were identified using a logistic regression model. Persistence was defined as time on continuous therapy; a Cox model identified predictors of prasugrel discontinuation.
  
  
  RESULTS
  Among 1,340 patients, the mean age was 57 years; 79.5 % were male. Median prasugrel MPR was 93.2 %; 69.0 % of patients had an MPR ≥80 %. Predictors of adherence <80 % included prior PCI [odds ratio (OR) 0.60; 95 % confidence interval (CI) 0.40-0.90], prior depression (OR 0.37; 95 % CI 0.16-0.84), prior bleeding (OR 0.41; 95 % CI 0.19-0.86), and baseline anticoagulant use (OR 0.13; 95 % CI 0.03-0.55). Baseline statin use predicted higher adherence (OR 1.56; 95 % CI 1.21-2.02). The median duration of prasugrel therapy was 259 days. Predictors of discontinuation included prior anemia [hazard ratio (HR) 1.63; 95 % CI 1.21-2.21], prior cardiomyopathy (HR 2.72; 95 % CI 1.44-5.13), and prior ischemic heart disease (HR 1.15; 95 % CI 1.00-1.32); baseline statin use predicted reduced risk of discontinuation (HR 0.85; 95 % CI 0.75-0.97).
  
  
  CONCLUSIONS
  Although adherence to prasugrel was generally high, the duration of therapy was frequently below recommendations. An awareness of risk factors for low adherence or early discontinuation can point to appropriate targets for intervention.
authors.affiliation: United BioSource Corporation, 430 Bedford Street, Suite 300, Lexington, MA 02420, USA. beth.nordstrom@unitedbiosource.com
authors.forename: Beth L
authors.initials: BL
authors.lastname: Nordstrom
authors.forename: Jason C
authors.initials: JC
authors.lastname: Simeone
authors.forename: Zhenxiang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Cliff
authors.initials: C
authors.lastname: Molife
authors.forename: Patrick L
authors.initials: PL
authors.lastname: McCollam
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.forename: Mark B
authors.initials: MB
authors.lastname: Effron
mesh_terms: D054058:Acute Coronary Syndrome / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010349:Patient Compliance; D062645:Percutaneous Coronary Intervention / Q000379:methods; D010879:Piperazines / Q000627:therapeutic use*; D000068799:Prasugrel Hydrochloride; D012189:Retrospective Studies; D013876:Thiophenes / Q000627:therapeutic use*
chemical_list: D010879:Piperazines; D013876:Thiophenes; D000068799:Prasugrel Hydrochloride