Clopidogrel Adherence

Study Questions:

What factors, including patient perceptions of clopidogrel and nuisance bleeding, predict adherence to clopidogrel therapy?


This was a cross-sectional study of subjects in a metropolitan area who were recruited through public media. Subjects completed a set of surveys to assess depressive symptoms, perceived social support, medications adherence, and attitudes toward medications. A validated survey of nuisance bleeding was designed for this study.


The study cohort included 106 subjects who were prescribed clopidogrel predominantly for coronary artery disease. Using previously described cutoff values, the subjects were classified as low adherence (55%), moderate adherence (28%), and high adherence (16%). The mean age of subjects was 72 years. Coronary artery disease provided the indication for clopidogrel in 71% of subjects. Neither demographic characteristics nor indication for clopidogrel were significant predictors of adherence. Hierarchical multiple linear regression identified three factors that were predictive of clopidogrel adherence:

  • Lower level of concern about clopidogrel
  • Higher perception of the need for clopidogrel
  • Increased severity of nuisance bleeding

Although the finding of a positive relationship between increased severity of nuisance bleeding and increased adherence is surprising, even counterintuitive, the authors suggest that it may reflect a lower level of concern about clopidogrel and provide reassurance of the medication effectiveness.


Concern about clopidogrel, confidence in the necessity of clopidogrel, and the severity of nuisance bleeding predict adherence. Providers should include these factors in patients’ counseling to promote self-monitoring and safe therapy.


Clopidogrel is widely used for antiplatelet therapy in cardiovascular disease. As this study reaffirms, many patients are not adherent to therapy, which may lead to adverse events and suboptimal outcomes. It is important for cardiovascular providers to be aware of the factors that promote adherence and assess those factors when counseling patients about proposed therapy.

Clinical Topics: Anticoagulation Management, Atherosclerotic Disease (CAD/PAD)

Keywords: Anticoagulants, Coronary Artery Disease, Counseling, Hemorrhage, Medication Adherence, Self Care

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