NVAF patients often don't get the right doses

Many patients with nonvalvular atrial fibrillation (NVAF) are not getting the recommended doses of direct oral anticoagulants (DOACs). This suggests “there is a need for efforts to improve the quality of direct oral anticoagulant use and dosing,” according to a study in JAMA Network Open. Overall, the paper showed “off-label dosing was not associated with improved adherence or lower risk of discontinuation of DOAC therapy. In addition, off-label dosing was not associated with reduced risk of bleeding while taking DOAC therapy,” the study said. To do the study, researchers used data from Symphony Health, a large, national medical and prescription claims data set that includes demographic, claims, laboratory, and prescription fill data for 280 million people, and prescriber information for 1.8 million prescribers in the U.S.. Patients were included if they had two claims for atrial fibrillation (AF) and one-year prescription history from between January 2015 and December 2017. Exclusion criteria included a history of mitral stenosis; history of mechanical or bioprosthetic mitral valve replacement or repair; those who lacked qualifying prescriptions or were under 18 years old. Data were analyzed for 86,919 patients. Four categories of oral anticoagulant dosing according to drug package labeling were examined: off-label underdosing; off-label excess dosing; appropriate reduced dose according; and appropriate full dose. The patients had a median age of 74 years; 43,724 (50.3%) were men; and 82,389 were White. Of these, 7,335 (8.4%) received an appropriately reduced dose, and 10,964 (12.6%) received a lower dose than what the FDA recommends. This means that significant numbers of those who received a reduced dose received an inappropriate dose, the study said. Recommended dosing in relation to renal dysfunction was taken into account. “Off-label dosing of a DOAC not according to FDA recommendations was associated with decreased anticoagulant adherence and increased likelihood of anticoagulant discontinuation, whereas on-label reduced dosing was not associated with either. Off-label reduced dosing was not associated with lower bleeding risk compared with on-label dosing,” the study said. Among patients with NVAF when stratified by degree of renal dysfunction, it was found that that more than one in five patients with creatinine clearance between 30 and 59 mL per minute were receiving off-label underdosed DOACs, and just under one in five with a creatinine clearance less than 30 mL per minute were being prescribed an off-label excess dose, the study said.

NVAF patients often don't get the right doses

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