Non‐vitamin K antagonist oral anticoagulant (NOAC) use and dosing in Canadian practice: Insights from the optimising pharmacotherapy in the management approach to lowering risk in atrial fibrillation (OPTIMAL AF) Programme

Abstract

Aims: To estimate the rate of non-vitamin K oral anticoagulant (NOAC) dosing that is lower-and higher-than-recommended and to describe the reasons for NOAC dose discordance with Health Canada prescribing information. Methods: The OPTIMAL AF Programme was an observational cohort quality assessment initiative in which primary and specialty care physicians in eight provinces provided a snapshot of their anticoagulated non-valvular atrial fibrillation (NVAF) patients through either an electronic medical record (EMR) system or standardised, paper-based data collection methods. Results: Data on 1681 NVAF patients receiving oral anticoagulation (OAC) for stroke prevention was provided by 102 physicians. A NOAC was prescribed in 1379 patients (8%). The standard recommended dose was prescribed in 849 (76%) and reduced dose in 264 (24%). Concordance of the reduced dose with Health Canada prescribing information occurred in 154 patients (58%). The standard dose was concordant in 805 (95%). The main reasons for the use of discordant reduced doses were age of 80 years or more, elevated creatinine, prior bleeding or dose recommended by specialist. Discussion and Conclusion: The vast majority of Canadian patients meeting the Canadian Cardiovascular Society (CCS) guideline recommendations for OAC to decrease AF-related stroke risk were receiving product monograph-concordant NOAC dosing (85%). Nonetheless, this highlights the fact that an important proportion of patients were prescribed doses that are discordant and opportunities remain to improve NOAC dosing to optimise stroke prevention.

Guideline Adherence As An Indicator of the Extent of Antithrombotic Overuse and Underuse: A Systematic Review

“…Study designs included 14 retrospective record reviews [ 20 21 22 23 24 25 26 27 28 29 30 31 32 33 ], 6 cohort studies [ 34 35 36 37 38 39 ] and 1 a case-control [ 40 ] (see Table 1 ). Four studies focused on overuse, 5on underuse, and 12 on both.…”

“…Large variation in the rates of antithrombotic overuse was observed across geographic regions with studies from Asia reporting the lowest levels of overuse (1.3–7.6%) [ 27 33 ], followed by Australia (24.1–42.9%) [ 20 23 24 ], and Europe (1.4–72.0%) [ 21 25 28 29 30 33 36 37 38 39 40 ], through to the highest variation in North America (6.6–73.0%) [ 26 31 32 34 35 ]. No clear time trend of increasing or decreasing overuse was observed over the period of the studies (2008–2020).…”

Direct oral anticoagulant dose selection: Challenging cases

“…While 50% of patients in the RE‐LY (Randomized Evaluation of Long‐Term Anticoagulant Therapy) trial were randomly assigned the lower dose of dabigatran, only 5%, 21%, and 25% of patients in factor Xa inhibitor trials received a reduced dose of apixaban, rivaroxaban, and edoxaban, respectively, according to prespecified criteria 8,9 . In contrast to the trials, between 24% and 39% of patients with AF prescribed a DOAC in the community receive a reduced dose, and of these, as many as 42% do not meet guideline criteria for dose reduction 10,11 . The most common reason for off‐label DOAC dose reduction is concern about the risk of bleeding because of advanced age, reduced renal function, frequent falls, previous bleeding, and concomitant antiplatelet therapy 11,12 …”

“…8,9 In contrast to the trials, between 24% and 39% of patients with AF prescribed a DOAC in the community receive a reduced dose, and of these, as many as 42% do not meet guideline criteria for dose reduction. 10,11 The most common reason for off-label DOAC dose reduction is concern about the risk of bleeding because of advanced age, reduced renal function, frequent falls, previous bleeding, and concomitant antiplatelet therapy. 11,12…”

“…10,11 The most common reason for off-label DOAC dose reduction is concern about the risk of bleeding because of advanced age, reduced renal function, frequent falls, previous bleeding, and concomitant antiplatelet therapy. 11,12…”