title: Dabigatran adherence in atrial fibrillation patients during the first year after diagnosis: a nationwide cohort study.
abstract: BACKGROUND
  There is a perception among physicians that lack of routine monitoring with non-vitamin K antagonist oral anticoagulants (NOACs) may lead to poor adherence to medication. We studied adherence during the first year of usage in a cohort of patients with newly diagnosed non-valvular atrial fibrillation (AF) started on the NOAC, dabigatran etexilate.
  
  
  RESULTS
  Nationwide Danish patient and prescription purchase registries were used to identify newly diagnosed AF patients taking dabigatran, comorbidities, and refill patterns under a twice-daily, one pill regimen. Adherence was characterized among remaining users (N = 2960) after 1 year using the proportion of days covered (PDC), gap rates and restart rates. The overall 1-year PDC was 83.9%, with 76.8% of patients having a 1-year PDC in excess of 80%. Patients with a CHA2 DS2 -VASc score ≥ 2 were more adherent to medication regimes than patients with a CHA2 DS2 -VASc score of 1 (PDC ratio, 1.12; 95% confidence interval [CI], 1.08-1.17) and generally patients with higher morbidity showed more adherence. Patients with prior bleeding were not less adherent to medication regimes than patients with no prior bleeding (PDC ratio, 1.02; 95% CI, 0.98-1.06). The overall gap rate was 1.4 gaps per year. There were no clear tendencies in gap rates among subgroups, although patients with higher morbidity tended to have slightly more, but shorter, gap periods.
  
  
  CONCLUSIONS
  More than 75% of patients were showed > 80% adherence to medication regimes during the first year. Patients with higher morbidity, including patients with a higher risk of stroke or bleeding, exhibited better adherence. This improvement may be attributable to more regular contact with the healthcare system.
authors.affiliation: Aalborg AF Study Group, Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark; Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Faculty of Health, Aalborg University, Aalborg, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Gorst-Rasmussen
authors.forename: F
authors.initials: F
authors.lastname: Skjøth
authors.forename: T B
authors.initials: TB
authors.lastname: Larsen
authors.forename: L H
authors.initials: LH
authors.lastname: Rasmussen
authors.forename: G Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: D A
authors.initials: DA
authors.lastname: Lane
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000991:Antithrombins / Q000008:administration & dosage* / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D000069604:Dabigatran / Q000008:administration & dosage* / Q000009:adverse effects; D003718:Denmark / Q000453:epidemiology; D011307:Drug Prescriptions; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000991:Antithrombins; D000069604:Dabigatran
keywords: anticoagulants; atrial fibrillation; dabigatran; medication adherence; pharmacoepidemiology