title: Predictors for prophylactic antithrombotic prescribing in ischaemic heart disease and the impact of national guidelines.
abstract: OBJECTIVE
  Assessment of predictors for initiating prophylactic antithrombotic prescribing for patients newly diagnosed with ischaemic heart disease (IHD) and the impact of the introduction of national guidelines.
  
  
  METHODS
  A retrospective case-control study was performed using pharmacy prescription data from 120,000 Dutch patients over a 5-year period. IHD patients were identified using as a marker multiple nitrate prescriptions [anatomical-chemical-therapeutic (ATC) code CO1D] indicating chronic use. Initiation of antithrombotic therapy was likewise identified using ATC codes B01AA and B01AC (oral anticoagulants and thrombocyte aggregation inhibitors), prescribed within 6 months following the first nitrate prescription. Statistically significant (P<0.05) predictors were assessed using multivariable analysis considering patient, prescriber and medication characteristics.
  
  
  RESULTS
  Of the 2598 patients who met specified inclusion criteria for newly diagnosed IHD, approximately 35% was not prescribed any type of antithrombotic therapy. Male patients [odds ratio (OR) 2.4, 95% confidence interval (CI) 2.0-2.9], patients with cardiovascular (other than IHD) and diabetic co-morbidity (OR 6.4, 95% CI 4.8-7.9 and OR 1.6, 95% CI 1.1-2.1, respectively) and patients using isosorbide mononitrate rather than isosorbide dinitrate as anti-ischaemic main therapy (OR 2.1, 95% CI 1.3-2.5) were most likely to be prescribed antithrombotic therapy. Furthermore, initiating antithrombotic prescribing was more likely after the introduction of national guidelines (OR 1.4, 95% CI 1.1-1.7).
  
  
  CONCLUSIONS
  Initiating antithrombotic prescribing in newly diagnosed IHD patients can be predicted by patient gender, certain co-morbidity and main type of nitrate therapy. The introduction of national guidelines has resulted in an increase of prophylactic antithrombotic prescribing in accordance with their contents.
authors.affiliation: Groningen University Institute for Drug Exploration, University of Groningen, University Centre for Pharmacy, Department of Pharmaceutical Pharmacology and Clinical Pharmacy, The Netherlands. R.Fijn@Farm.rug.nl
authors.forename: R
authors.initials: R
authors.lastname: Fijn
authors.forename: A G
authors.initials: AG
authors.lastname: Stuurman-Bieze
authors.forename: P B
authors.initials: PB
authors.lastname: van den Berg
authors.forename: J R
authors.initials: JR
authors.lastname: Brouwers
authors.forename: P A
authors.initials: PA
authors.lastname: de Graeff
authors.forename: L T
authors.initials: LT
authors.lastname: de Jong-van den Berg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D017408:Guidelines as Topic; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000517:prevention & control*; D009426:Netherlands; D012189:Retrospective Studies
chemical_list: D005343:Fibrinolytic Agents