Self-reported adherence to anticoagulation and its determinants using the Morisky medication adherence scale.
BACKGROUND
Direct oral anticoagulants (DOACs) are used for treatment of venous thromboembolism (VTE) and stroke prevention in atrial fibrillation (AF). Given the shorter half-life and lack of laboratory monitoring compared to vitamin-K antagonists (VKAs), adequate adherence to DOACs is important. Reported anticoagulation adherence is unclear in clinical practice.


OBJECTIVE
To assess self-reported anticoagulation adherence in a tertiary center anticoagulation clinic.


METHODS
Cross-sectional study of patients on oral anticoagulants (VKAs, rivaroxaban, dabigatran and apixaban). Anticoagulation adherence was assessed using the 4-item Morisky score. Baseline characteristics were evaluated for association with adherence.


RESULTS
Five hundred patients completed the survey; 74% were on VKAs and 26% on DOACs: rivaroxaban 102 (79%); dabigatran 26 (19%); apixaban 2 (2%). Main indications for anticoagulation were VTE (72%) and AF (18%). Self-reported anticoagulation adherence using the 4-item Morisky scale was 56.2% for patients on VKAs and 57.1% for patients on DOACs. Predictors of anticoagulation adherence were age (OR=1.02; 95% CI:1.01-1.03), female gender (OR=1.58; 95% CI:1.10-2.27), use of additional oral medications (OR=2.78; 95% CI:1.67-4.63), and retired employment status (OR=2.31; 95% CI:1.51-3.55). In backward selection multivariate analyses age, female gender and use of other oral medications remained significantly associated with anticoagulation adherence.


CONCLUSIONS
Self-reported anticoagulation adherence was similar between VKAs and DOACs. Until laboratory assays are universally available to evaluate DOAC adherence, physicians should emphasize the importance of anticoagulation adherence at each patient encounter. The Morisky scale provides simple assessment of anticoagulation adherence; however it has not yet been validation for this purpose.
Department of Medicine at The Ottawa Hospital, Ottawa Hospital Research Institute, University of Ottawa,501 Smyth Road, Ottawa, Ontario,K1H 8L6, Canada. Electronic address: lcastellucci@toh.on.ca.
Lana A
LA
Castellucci
Department of Medicine at The Ottawa Hospital, Ottawa Hospital Research Institute, University of Ottawa,501 Smyth Road, Ottawa, Ontario,K1H 8L6, Canada.
Joseph
J
Shaw
Department of Family Medicine, School for Public Health and Primary Care (CAPHRI), Maastricht University Medical Centre, Universiteitssingel 40 6229 ER Maastricht,The Netherlands.
Katrien
K
van der Salm
Department of Internal Medicine, Laboratory for Clinical Thrombosis and Haemostasis, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre, Universiteitssingel 40 6229 ER Maastricht, The Netherlands; Department of Clinical Epidemiology, School for Public Health and Primary Care (CAPHRI), Maastricht University Medical Centre, Universiteitssingel 40 6229 ER Maastricht, The Netherlands.
Petra
P
Erkens
Department of Medicine at The Ottawa Hospital, Ottawa Hospital Research Institute, University of Ottawa,501 Smyth Road, Ottawa, Ontario,K1H 8L6, Canada; Montfort Hospital Research Institute, University of Ottawa, 202-745A Montreal Road, Ottawa, Ontario, K1K 0T2, Canada.
Gregoire
G
Le Gal
Department of Medicine at The Ottawa Hospital, Ottawa Hospital Research Institute, University of Ottawa,501 Smyth Road, Ottawa, Ontario,K1H 8L6, Canada.
William
W
Petrcich
Department of Medicine at The Ottawa Hospital, Ottawa Hospital Research Institute, University of Ottawa,501 Smyth Road, Ottawa, Ontario,K1H 8L6, Canada; Montfort Hospital Research Institute, University of Ottawa, 202-745A Montreal Road, Ottawa, Ontario, K1K 0T2, Canada.
Marc
M
Carrier
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D057566:Self Report; D011795:Surveys and Questionnaires; D054556:Venous Thromboembolism / Q000188:drug therapy*; D055815:Young Adult
D000925:Anticoagulants
Anticoagulant; Medication adherence; Self-report; Survey; Venous thromboembolism