Community pharmacy-based study of adherence to non-vitamin K antagonist oral anticoagulants

Heart. 2020 Nov;106(22):1740-1746. doi: 10.1136/heartjnl-2020-316781. Epub 2020 Jun 23.


Objective: This study aimed to assess implementation adherence (how well the patient's actual intake matches the prescribed dosing regimen) to non-vitamin K antagonist oral anticoagulants (NOACs) and to explore experiences with and beliefs about NOACs in a real-world sample of long-term NOAC users.

Methods: A cross-sectional observational study was conducted in home-dwelling adults who started taking a NOAC at least 1 year prior to inclusion. Pharmacy dispensing data were used to calculate the Medication Possession Ratio (MPR). Patients were recruited in 158 community pharmacies in Flanders, Belgium. They completed a questionnaire collecting basic characteristics and exploring self-reported adherence to NOACs (using the Medication Adherence Report Scale, MARS) and experiences with and beliefs about NOACs (using the Beliefs about Medicines Questionnaire, BMQ).

Results: A total of 766 patients (mean age 76.2±8.8 years, median CHA2DS2-VASc score 4 (IQR=3-4)) were included. The majority (93.5%) used NOAC for stroke prevention in atrial fibrillation. The median MPR was 95.2% (IQR=87.8-99.7) which corresponds with half of the study population not taking their NOAC on at least 17 cumulative days per year. Almost 21% of participants reported non-adherence on the MARS (score <25), with unintentional non-adherence (forgetfulness) most frequently reported (15.4%). Although two-thirds of NOAC users indicated to experience adverse drug reactions, the BMQ demonstrated a positive attitude towards NOAC therapy, where necessity beliefs outweigh the concerns.

Conclusions: Our data indicate that long-term NOAC users have high implementation adherence and a positive attitude towards NOAC therapy. However, taking into account patients' thromboembolic risk and NOACs' short half-lives, further optimisation of NOAC use seems warranted in this population.

Keywords: atrial fibrillation; pharmacology.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Administration, Oral
  • Aged
  • Anticoagulants / administration & dosage*
  • Atrial Fibrillation / complications
  • Atrial Fibrillation / drug therapy*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Medication Adherence / statistics & numerical data*
  • Pharmacies / statistics & numerical data*
  • Retrospective Studies
  • Risk Factors
  • Thromboembolism / etiology
  • Thromboembolism / prevention & control*


  • Anticoagulants