Log in to MyACC
Oral Anticoagulant Prescription Trends and Adherence Determinants in AF
Study Questions:
What are the prescription trends and determinants of adherence to oral anticoagulants post hospital discharge for patients with new atrial fibrillation?
Methods:
A cohort of 33,311 new oral anticoagulant users were identified from administrative databases (hospital discharges from MED-ECHO, medical services and public drug plan). Data claims were used for the retrospective analysis from Régie de l'Assurance Maladie du Québec and MED-ECHO. Patients aged 18 and older with a primary or secondary diagnosis of atrial fibrillation between January 1, 2011, and March 31, 2017, who were discharged alive were included. New users (not on direct oral anticoagulant [DOAC] or warfarin for 1 year prior to cohort entry) were defined by having a new prescription of dabigatran (110 mg or 150 mg BID), rivaroxaban (15 and 20 mg daily), or apixaban (2.5 or 5 mg BID). Persistent use was defined as refilling oral anticoagulant prescriptions. Adherence was evaluated using proportion of days covered (PDC), which is total days of medication supply divided by 365 days, stated as a percentage. Adherent patients were defined as having PDC ≥80% and 90%.
Results:
From 2011 to 2017, patient initiation of DOACs increased from 22.1% to 87.3%, whereas warfarin use decreased from 77.9% to 12.7%. Oral anticoagulant use by December 2017 was predominantly apixaban 2.5 or 5 mg (60.1%) and rivaroxaban 20 mg (17.5%). Warfarin claims decreased by almost 80% overall. Persistence rates were higher in the DOAC groups, with apixaban 5 mg users significantly more persistent than others (p < 0.0001) except for dabigatran 150 mg and rivaroxaban 20 mg. Lowest persistence rates at 1 year were with warfarin (53%). Over the year, about 75% of oral anticoagulant users were adherent (PDC ≥80%). Of the approximately 25% non-adherent users (PDC <80 %), rates ranged from 43.1% to 50.7%. High adherence levels were found in patients of older age, female gender, higher CHA2DS2-VASc score, prescribed higher doses of oral anticoagulants, with stoke history, and on medications for chronic cardiovascular disease. Low adherence was observed in patients with a higher Charlson Comorbidity Index score.
Conclusions:
Over the study period from 2011 to 2017, warfarin use decreased and DOAC use significantly increased. Low adherence levels were found in 25% of new oral anticoagulant patients. This study may help to identify patients who could benefit from counseling to increase adherence rates by oral anticoagulant type and dose, comorbidities, and concomitant medications.
Perspective:
To increase adherence to oral anticoagulant therapy, counseling on the significance of adherence should be emphasized in patients who are younger, male, with lower CHA2DS2-VASc scores, on lower doses of oral anticoagulants, with no history of stroke, and not on medications for chronic cardiovascular disease.
Keywords: Anticoagulants, Atrial Fibrillation, Medication Adherence, Patient Discharge, Comorbidity, Counseling
< Back to Listings
