Predictors for prophylactic antithrombotic prescribing in ischaemic heart disease and the impact of national guidelines.
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.
Fijn
R
R
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
Stuurman-Bieze
A G
AG
van den Berg
P B
PB
Brouwers
J R
JR
de Graeff
P A
PA
de Jong-van den Berg
L T
LT
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
D005343:Fibrinolytic Agents